Cheap flights from St. Louis to Ontario (STL - ONT) from $63

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 6/14. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
STL — ONT
May 12 — May 191

The best prices from Lambert-St Louis to Ontario are usually found in April or August, booked 33 days in advance, depart on a Thursday or Tuesday and return on a Saturday

Cheap flight deals from St. Louis to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Ontario (ONT). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated May 7, 2024.

Popular in

December

Cheapest in

April

Round-trip from

$238

One-way from

$175
High demand for flights, 29% potential price rise
Best time to find cheap flights, 49% potential price drop
From Lambert-St Louis to Ontario
One-way flight from Lambert-St Louis to Ontario

What is the cheapest day to fly round-trip from St. Louis to Ontario?

Thursday flights are generally found to be more expensive for flights from St. Louis to Ontario. This shouldn’t discourage you from searching, as you can still find great deals by being flexible with your options. Use our search form to find deals on tickets to Ontario.

How far in advance should I book a flight from St. Louis to Ontario?

Travelers have found it’s best to book a flight 37 days in advance to save up to 108% compared to booking the same week of travel. As your travel date approaches, the cost of this flight route may potentially increase. While opting to book 37 days out may not be an option for all, there are still additional ways to secure a deal in the near future. You might find a flight from St. Louis to Ontario 1-2 weeks in advance for as low as $589, or $654 for flights within the next 24 hours.

What is the cheapest month to fly from St. Louis to Ontario?

Our data shows that April tends to be the cheapest month to fly to Ontario from St. Louis. Users have commonly found prices around $413 for the month, but tickets can be as low as $185. Due to multiple factors, prepare for potentially higher prices in March.

When is the cheapest time to fly from St. Louis to Ontario (STL - ONT)?

It’s optimal to fly from St. Louis to Ontario in the evening. By choosing this option you can save up to 57% on the cost of your flight, compared to a flight at noon.

Cheap Frontier flights from St. Louis to Ontario

Explore cheap flight options specifically provided by Frontier for the route between St. Louis and Ontario. Find affordable fares and compare prices with other airlines to secure the best deal for your journey. Over the last 7 days, Cheapflights users made 2,689,106 searches. Data last updated May 7, 2024.
Consider these cheap Frontier flights we've found departing from St. Louis to Ontario. Make sure to double check the flight details before booking.
Mon 6/38:04 pmSTL - ONT
1 stop5h 55mFrontier
Sun 6/912:59 amONT - STL
1 stop6h 30mFrontier
Deal found 5/6$126
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Tue 5/2110:42 pmONT - STL
1 stop9h 31mFrontier
Deal found 5/6$129
Thu 5/237:23 pmSTL - ONT
1 stop22h 16mFrontier
Wed 5/297:45 pmONT - STL
1 stop12h 28mFrontier
Deal found 5/6$132
Mon 6/38:04 pmSTL - ONT
1 stop5h 55mFrontier
Thu 6/1310:29 pmONT - STL
1 stop11h 25mFrontier
Deal found 5/6$133
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Mon 5/2012:59 amONT - STL
1 stop10h 10mFrontier
Deal found 5/6$134
Mon 6/38:04 pmSTL - ONT
1 stop5h 55mFrontier
Wed 6/58:03 amONT - STL
1 stop28h 29mFrontier
Deal found 5/6$136
Sat 6/17:23 pmSTL - ONT
1 stop14h 11mFrontier
Fri 6/712:48 amONT - STL
1 stop6h 41mFrontier
Deal found 5/5$138
Sat 5/2511:41 pmSTL - ONT
1 stop8h 36mFrontier
Fri 5/3112:59 amONT - STL
1 stop6h 26mFrontier
Deal found 5/6$140
Thu 5/237:23 pmSTL - ONT
1 stop16h 01mFrontier
Sun 6/212:59 amONT - STL
1 stop6h 37mFrontier
Deal found 5/6$144

Cheap American Airlines flights from St. Louis to Ontario

Explore cheap flight options specifically provided by American Airlines for the route between St. Louis and Ontario. Find affordable fares and compare prices with other airlines to secure the best deal for your journey. Over the last 7 days, Cheapflights users made 2,689,106 searches. Data last updated May 7, 2024.
Have a look at some of the cheapest available American Airlines flights departing from St. Louis and landing in Ontario. If these deals don't fit your criteria, make sure to check back soon as new deals are always added.
Mon 7/13:27 pmSTL - ONT
1 stop9h 32mAmerican Airlines
Fri 7/59:19 amONT - STL
2 stops9h 28mAmerican Airlines
Deal found 5/6$357
Sat 5/255:21 amSTL - ONT
2 stops8h 26mAmerican Airlines
Sat 6/112:53 pmONT - STL
1 stop9h 03mAmerican Airlines
Deal found 5/6$532
Sat 7/208:01 amSTL - ONT
1 stop5h 50mAmerican Airlines
Sat 7/202:47 pmONT - STL
1 stop6h 05mAmerican Airlines
Deal found 5/6$760
Thu 5/2310:46 amSTL - ONT
1 stop10h 13mAmerican Airlines
Tue 5/2812:53 pmONT - STL
2 stops8h 06mAmerican Airlines
Deal found 5/6$769
Sun 7/147:00 amSTL - ONT
1 stop6h 51mAmerican Airlines
Sun 7/142:47 pmONT - STL
1 stop6h 05mAmerican Airlines
Deal found 5/6$770
Fri 6/1412:44 pmSTL - ONT
2 stops7h 53mAmerican Airlines
Sat 6/226:30 amONT - STL
2 stops10h 47mAmerican Airlines
Deal found 5/6$776

Cheap St. Louis to Ontario flights in May & June 2024

Find cheap flight options from St. Louis to Ontario specifically for the months of May and June 2024. Explore affordable fares based on user searches. Over the last 7 days, Cheapflights users made 2,689,106 searches. Prices were last updated on May 7, 2024.
Scroll through some of the best deals on flights from St. Louis to Ontario in 2024. For more flight deals, be sure to check back very soon.
Mon 6/38:04 pmSTL - ONT
1 stop5h 55mFrontier
Sun 6/912:59 amONT - STL
1 stop6h 30mFrontier
Deal found 5/6$126
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Tue 5/2110:42 pmONT - STL
1 stop9h 31mFrontier
Deal found 5/6$129
Thu 5/237:23 pmSTL - ONT
1 stop22h 16mFrontier
Wed 5/297:45 pmONT - STL
1 stop12h 28mFrontier
Deal found 5/6$132
Mon 6/38:04 pmSTL - ONT
1 stop5h 55mFrontier
Thu 6/1310:29 pmONT - STL
1 stop11h 25mFrontier
Deal found 5/6$133
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Mon 5/2012:59 amONT - STL
1 stop10h 10mFrontier
Deal found 5/6$134
Mon 6/38:04 pmSTL - ONT
1 stop5h 55mFrontier
Wed 6/58:03 amONT - STL
1 stop28h 29mFrontier
Deal found 5/6$136
Sat 6/17:23 pmSTL - ONT
1 stop14h 11mFrontier
Fri 6/712:48 amONT - STL
1 stop6h 41mFrontier
Deal found 5/5$138
Sat 5/2511:41 pmSTL - ONT
1 stop8h 36mFrontier
Fri 5/3112:59 amONT - STL
1 stop6h 26mFrontier
Deal found 5/6$140
Thu 5/237:23 pmSTL - ONT
1 stop16h 01mFrontier
Sun 6/212:59 amONT - STL
1 stop6h 37mFrontier
Deal found 5/6$144

St. Louis to Ontario 2024 flight deals

Discover exclusive flight deals for travel between St. Louis and Ontario in 2024. Find excellent offers based on user searches. Over the last 7 days, Cheapflights users made 2,689,106 searches. Data last updated May 7, 2024.
Scroll through some of the best deals on flights from St. Louis to Ontario in 2024. For more flight deals, be sure to check back very soon.
Mon 6/38:04 pmSTL - ONT
1 stop5h 55mFrontier
Sun 6/912:59 amONT - STL
1 stop6h 30mFrontier
Deal found 5/6$126
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Tue 5/2110:42 pmONT - STL
1 stop9h 31mFrontier
Deal found 5/6$129
Thu 5/237:23 pmSTL - ONT
1 stop22h 16mFrontier
Wed 5/297:45 pmONT - STL
1 stop12h 28mFrontier
Deal found 5/6$132
Mon 6/38:04 pmSTL - ONT
1 stop5h 55mFrontier
Thu 6/1310:29 pmONT - STL
1 stop11h 25mFrontier
Deal found 5/6$133
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Mon 5/2012:59 amONT - STL
1 stop10h 10mFrontier
Deal found 5/6$134
Mon 6/38:04 pmSTL - ONT
1 stop5h 55mFrontier
Wed 6/58:03 amONT - STL
1 stop28h 29mFrontier
Deal found 5/6$136
Sat 6/17:23 pmSTL - ONT
1 stop14h 11mFrontier
Fri 6/712:48 amONT - STL
1 stop6h 41mFrontier
Deal found 5/5$138
Sat 5/2511:41 pmSTL - ONT
1 stop8h 36mFrontier
Fri 5/3112:59 amONT - STL
1 stop6h 26mFrontier
Deal found 5/6$140
Thu 5/237:23 pmSTL - ONT
1 stop16h 01mFrontier
Sun 6/212:59 amONT - STL
1 stop6h 37mFrontier
Deal found 5/6$144

St. Louis to Ontario flights leaving soon

Find last-minute flight options from St. Louis to Ontario for spontaneous travel. Discover available flights and compare prices based on user searches. Secure great deals and offers for spontaneous trips with quick booking options. Over the last 7 days, Cheapflights users made 2,689,106 searches. Data last updated May 7, 2024.
Have a look at some of the last-minute flights available departing from St. Louis to Ontario. It's wise to confirm all flight details are correct before booking.
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Tue 5/2110:42 pmONT - STL
1 stop9h 31mFrontier
Deal found 5/6$129
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Wed 5/225:41 pmONT - STL
1 stop14h 32mFrontier
Deal found 5/6$132
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Mon 5/2012:59 amONT - STL
1 stop10h 10mFrontier
Deal found 5/6$134
Tue 5/1410:59 pmSTL - ONT
1 stop10h 09mFrontier
Wed 5/1511:09 pmONT - STL
1 stop9h 04mFrontier
Deal found 5/6$140
Thu 5/1611:06 pmSTL - ONT
1 stop26h 53mFrontier
Sun 5/196:09 pmONT - STL
1 stop14h 04mFrontier
Deal found 5/6$147
Fri 5/176:40 pmSTL - ONT
1 stop16h 24mFrontier
Sun 5/1911:30 pmONT - STL
1 stop8h 43mFrontier
Deal found 5/6$148
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Mon 5/2012:59 amONT - STL
1 stop10h 10mFrontier
Deal found 5/6$155
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Thu 5/1612:59 amONT - STL
1 stop6h 37mFrontier
Deal found 5/6$159
Thu 5/167:23 pmSTL - ONT
1 stop25h 00mFrontier
Sat 5/1812:59 amONT - STL
1 stop19h 33mFrontier
Deal found 5/6$165

One-way flights to Ontario from St. Louis

Search for one-way flight options from St. Louis to Ontario. Find affordable one-way fares based on user searches. Compare prices and availability to plan your one-way journey according to your preferred dates and budget. Over the last 7 days, Cheapflights users made 2,689,106 searches. Data last updated May 7, 2024.
Users in need of a one-way flight from St. Louis to Ontario can choose from these deals. Users in need of a round-trip flight from St. Louis to Ontario instead should update the search form at the top of page.
Fri 6/145:36 pmSTL - ONT
1 stop5h 47mFrontier
Deal found 5/6$63
Wed 5/2210:21 pmSTL - ONT
1 stop12h 19mFrontier
Deal found 5/6$65
Mon 5/207:23 pmSTL - ONT
1 stop19h 31mFrontier
Deal found 5/6$69
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Deal found 5/6$70
Fri 6/145:36 pmSTL - ONT
1 stop5h 47mFrontier
Deal found 5/6$74
Tue 5/1410:59 pmSTL - ONT
1 stop10h 09mFrontier
Deal found 5/6$76
Sat 6/157:29 pmSTL - ONT
1 stop13h 34mFrontier
Deal found 5/6$80
Tue 5/287:23 pmSTL - ONT
1 stop15h 41mFrontier
Deal found 5/6$81
Wed 6/57:29 pmSTL - ONT
1 stop17h 27mFrontier
Deal found 5/6$87

Find flights from St. Louis to Ontario within your budget

Customize your flight search to find flights from St. Louis to Ontario that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,689,106 searches. Data last updated May 7, 2024.

Fly from

Any airport

Fly to

Any airport

Budget

$126 - $378

Route

Depart

Return

Price

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Mon 6/3

1 stop5h 55m

Ontario

Sun 6/9

1 stop6h 30m

$126

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Wed 5/15

1 stop7h 21m

Ontario

Tue 5/21

1 stop9h 31m

$129

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Thu 5/23

1 stop22h 16m

Ontario

Wed 5/29

1 stop12h 28m

$132

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Mon 6/3

1 stop5h 55m

Ontario

Thu 6/13

1 stop11h 25m

$133

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Wed 5/15

1 stop7h 21m

Ontario

Mon 5/20

1 stop10h 10m

$134

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Mon 6/3

1 stop5h 55m

Ontario

Wed 6/5

1 stop28h 29m

$136

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Sat 6/1

1 stop14h 11m

Ontario

Fri 6/7

1 stop6h 41m

$138

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Mon 7/1

1 stop9h 32m

Ontario

Fri 7/5

2 stops9h 28m

$357

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Mon 6/3

1 stop9h 20m

Ontario

Wed 6/5

2 stops11h 34m

$378

Flights are sorted by cheapest first

Deals found on 5/6

When is the best time to book a flight from St. Louis to Ontario?

Use this chart to determine the optimal time to book a round-trip flight from St. Louis to Ontario. Price data was last updated on May 3, 2024.
The price you pay for your flight from St. Louis to Ontario may vary depending on when you book. For the best chance of a lower fare, look to book 33 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.
Search Deals

When is the cheapest time to fly from St. Louis to Ontario?

Use this chart to determine the cheapest time to fly round-trip from St. Louis to Ontario. Price data was last updated on May 5, 2024.
Morning
Noon
Afternoon
Evening
All times are departure.
Travelers seeking maximum savings on their St. Louis to Ontario flight should consider departing on Sunday at noon when fares are most often at their lowest. Friday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
Search Deals

Average price of flights to Ontario by month

Plan your trip from St. Louis to Ontario by taking into account the cheapest months to travel. The average price of a one-way flight from St. Louis to Ontario is currently $74 while a round-trip flight costs $185. Price data was last updated on April 28, 2024.

Currently, October is the cheapest month in which you can book a flight from St. Louis to Ontario (average of $237). Flying from St. Louis to Ontario in June is currently the most expensive (average of $341). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

January

$268

February

$287

March

$281

April

$256

May

$268

June

$341

July

$336

August

$287

September

$258

October

$237

November

$268

December

$271

Temperature and rainfall in Ontario by month

Plan your trip to Ontario by taking into account the average temperature and rainfall totals by month.

LAX

Temperature

57.2 - 73.4 °F

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Ontario. Reviews last updated May 7, 2024.
Peruse reviews from past customers who have flown with Frontier, American Airlines and Delta from St. Louis to Ontario to help guide your decision. In addition to providing an overall rating, users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
8.1
Very good
9,137 reviews

Crew

8.6

Boarding

8.2

Comfort

7.9

Overall

8.1

Entertainment

7.3

Food

7.3

Reviews

1 / 10

We paid $161 for two exit row seats thinking there’d be extra leg room and not be cramped! The price we paid was a rip-off for these seats and the plane was extremely narrow and cramped. The male crew were okay but not super-friendly. When we picked up our luggage at baggage claim, someone ripped my luggage with a knife or blunt object and destroyed it!! I will be filling a claim for this and took pictures. I heard great reviews about this airline but am disappointed.

8.1
Very good
9,137 reviews
8.1
Very good
9,137 reviews

Crew

8.6

Boarding

8.2

Comfort

7.9

Overall

8.1

Entertainment

7.3

Food

7.3

Reviews

1 / 10

We paid $161 for two exit row seats thinking there’d be extra leg room and not be cramped! The price we paid was a rip-off for these seats and the plane was extremely narrow and cramped. The male crew were okay but not super-friendly. When we picked up our luggage at baggage claim, someone ripped my luggage with a knife or blunt object and destroyed it!! I will be filling a claim for this and took pictures. I heard great reviews about this airline but am disappointed.

8.1
Very good
10,818 reviews
8.1
Very good
9,137 reviews

Crew

8.6

Boarding

8.2

Comfort

7.9

Overall

8.1

Entertainment

7.3

Food

7.3

Reviews

1 / 10

We paid $161 for two exit row seats thinking there’d be extra leg room and not be cramped! The price we paid was a rip-off for these seats and the plane was extremely narrow and cramped. The male crew were okay but not super-friendly. When we picked up our luggage at baggage claim, someone ripped my luggage with a knife or blunt object and destroyed it!! I will be filling a claim for this and took pictures. I heard great reviews about this airline but am disappointed.

7.4
Good
11,090 reviews
8.1
Very good
9,137 reviews

Crew

8.6

Boarding

8.2

Comfort

7.9

Overall

8.1

Entertainment

7.3

Food

7.3

Reviews

1 / 10

We paid $161 for two exit row seats thinking there’d be extra leg room and not be cramped! The price we paid was a rip-off for these seats and the plane was extremely narrow and cramped. The male crew were okay but not super-friendly. When we picked up our luggage at baggage claim, someone ripped my luggage with a knife or blunt object and destroyed it!! I will be filling a claim for this and took pictures. I heard great reviews about this airline but am disappointed.

7.3
Good
14,697 reviews
8.1
Very good
9,137 reviews

Crew

8.6

Boarding

8.2

Comfort

7.9

Overall

8.1

Entertainment

7.3

Food

7.3

Reviews

1 / 10

We paid $161 for two exit row seats thinking there’d be extra leg room and not be cramped! The price we paid was a rip-off for these seats and the plane was extremely narrow and cramped. The male crew were okay but not super-friendly. When we picked up our luggage at baggage claim, someone ripped my luggage with a knife or blunt object and destroyed it!! I will be filling a claim for this and took pictures. I heard great reviews about this airline but am disappointed.

6.3
Okay
4,088 reviews
8.1
Very good
9,137 reviews

Crew

8.6

Boarding

8.2

Comfort

7.9

Overall

8.1

Entertainment

7.3

Food

7.3

Reviews

1 / 10

We paid $161 for two exit row seats thinking there’d be extra leg room and not be cramped! The price we paid was a rip-off for these seats and the plane was extremely narrow and cramped. The male crew were okay but not super-friendly. When we picked up our luggage at baggage claim, someone ripped my luggage with a knife or blunt object and destroyed it!! I will be filling a claim for this and took pictures. I heard great reviews about this airline but am disappointed.

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Ontario. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
  • Can I find flights from St. Louis to Ontario for under $200 on Cheapflights?

    Yes, there are multiple flights from St. Louis to Ontario for under $200. The cheapest flight booked recently is on Frontier for just $126, but on average you can expect to pay $144.

  • Are there last-minute flights available from St. Louis to Ontario for under $200?

    There are currently 19+ open flights from St. Louis to Ontario within the next 7 days for less than $200.

  • What is the cheapest airline to fly from St. Louis to Ontario round-trip?

    Frontier, at $126, was found to be the cheapest airline from St. Louis to Ontario.. Frontier is priced at 64% lower than the current average price of a flight leaving 3 months from now.

  • What are the cheapest airlines to fly from St. Louis to Ontario one-way?

    The cheapest airline one-way is Frontier, with whom users have recently found tickets for as low as $63. However, be on the lookout for offers from Delta and United Airlines, as they are both options that can get you from St. Louis to Ontario for a low price.

  • What are the most popular airlines that fly from St. Louis to Ontario?

  • What does STL to ONT mean?

    Lambert-St Louis Airport is STL and Ontario Airport is ONT. These codes are created by the International Air Transport Association (IATA) and airlines use them to identify the departing and arrival airports in the flight routes they service.

  • Can I find deals for flights from St. Louis to Ontario that include extra baggage allowance?

    The amount of baggage you can bring on your St. Louis to Ontario flight depends on the airline and the type of fare you've chosen. After entering your flight details, you'll be able to view the specific baggage policies for each deal in the search results. Keep in mind that certain deals may offer additional baggage allowance.

  • Can I find deals on flights from St. Louis to Ontario with specific airlines?

    Yes, Cheapflights allows you to browse and filter St. Louis to Ontario flight deals by airline. After entering your origin and destination, use the available filters to view flights offered by airlines.

  • Can I find deals for flights from St. Louis to Ontario that include hotel bookings?

    Yes. In addition to deals on St. Louis to Ontario flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from St. Louis to Ontario?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from St. Louis to Ontario.

  • Can I find deals for business class flights from St. Louis to Ontario?

    Yes. Cheapflights offers flight deals from St. Louis to Ontario by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • Can I find deals for flights from St. Louis to Ontario that allow pets onboard?

    Many airlines flying from St. Louis to Ontario offer the option to travel with pets. After selecting a flight deal, you can find more information about the airline's pet policy on their official website or by contacting the airline directly. Please note that additional fees and restrictions may apply.

  • Can I find deals on last-minute flights from St. Louis to Ontario?

    Yes, you can often find last-minute deals on St. Louis to Ontario flights on Cheapflights. However, these deals can vary and may not always be available. We recommend checking back frequently or signing up for price alerts for the most up-to-date deals.

  • How recently were the St. Louis to Ontario flight deals updated?

    The St. Louis to Ontario flight deals you see on this page were last updated on 5/6.

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for St. Louis to Ontario
See prices for flight routes from nearby airports that may be better suited for you.

Top 4 airlines flying from St. Louis to Ontario

Discover the top 4 airlines that operate flights from St. Louis to Ontario. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,689,106 searches. Data last updated May 7, 2024.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$120Average$223FlexibilityNo cancel feeOn-time62%
Search Frontier flights
DeltaCheapest$286Average$407FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
American AirlinesCheapest$309Average$494FlexibilityNo cancel feeOn-time71%
Search American Airlines flights
United AirlinesCheapest$337Average$621FlexibilityNo cancel feeOn-time69%
Search United Airlines flights

Search flights from St. Louis to Ontario by cabin class

Find flights from St. Louis to Ontario, based on your preferred cabin class, be it economy, premium economy, business, or first class.

Hourly flight availability from St. Louis to Ontario

Find hourly flight availability from St. Louis to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated May 7, 2024.
0%of flight departuresEarly morningMidnight to 6 am
0%of flight departuresMorning6 am to noon
0%of flight departuresAfternoonNoon to 6 pm
100%of flight departuresEvening6 pm to midnight
Midnight
6 AM
Noon
6 PM

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travelers can enjoy low prices and a wide availability of flights to their desired destinations.

How does Cheapflights help users find flights from St. Louis to Ontario?

When you search for this flight from St. Louis to Ontario, Cheapflights searches on 900+ travel sites to save you time finding great flight deals online. Additionally, we offer filter features so you can choose a preferred cabin class or airline, see different price ranges, and much more so you can book the flight for you.

Why should you use Cheapflights to find cheap flight tickets from St. Louis to Ontario?

Cheapflights taps into our reliable network of hundreds of airlines and travel agencies to find the best deals for flights from St. Louis to Ontario for you. Better yet — we are completely free to use.

Can Cheapflights find flights from St. Louis to Ontario with no change fees?

Certainly. Search results for flights to Ontario from St. Louis shown to you on Cheapflights can be narrowed down with different useful search filters, which includes flexible booking options.

Can Cheapflights notify me if prices for flights from St. Louis to Ontario become cheaper?

Yes! Start tracking prices for St. Louis to Ontario flights today and get alerted whenever prices for these flights change. To access this feature, click the bell icon next to the flight deals above, which will prompt you for a valid email address to receive your alerts.

100% Free
Cheapflights is completely free to use, so you can start saving the moment you arrive.
Book with Flexibility
Our users can plan ahead with confidence and find flights with no change fees
Travel Smart
Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.