Cheap flights from St. Louis to Ontario (STL - ONT) from $53

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 5/8. 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 2 — May 91

The best prices from Lambert-St Louis to Ontario are usually found in August or September, booked 38 days in advance, depart on a Thursday or Monday 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 April 27, 2024.

Popular in

June

Cheapest in

August

Round-trip from

$238

One-way from

$139
High demand for flights, 34% potential price rise
Best time to find cheap flights, 46% 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 58 days in advance to save up to 30% 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 58 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 $477, or $754 for flights within the next 24 hours.

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

Our data shows that January tends to be the cheapest month to fly to Ontario from St. Louis. Users have commonly found prices around $446 for the month, but tickets can be as low as $177. 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 56% on the cost of your flight, compared to a flight at noon.

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 3,068,117 searches. Data last updated April 27, 2024.
Consider these cheap American Airlines flights we've found departing from St. Louis to Ontario. Make sure to double check the flight details before booking.
Thu 5/165:21 amSTL - ONT
2 stops8h 26mAmerican Airlines
Mon 5/2010:29 pmONT - STL
1 stop9h 24mAmerican Airlines
Deal found 4/26$412
Wed 5/155:21 amSTL - ONT
2 stops8h 26mAmerican Airlines
Sun 5/196:00 amONT - STL
1 stop6h 13mAmerican Airlines
Deal found 4/26$431
Wed 7/1710:19 amSTL - ONT
2 stops10h 03mAmerican Airlines
Tue 7/234:31 pmONT - STL
1 stop5h 24mAmerican Airlines
Deal found 4/26$441
Sat 9/289:50 amSTL - ONT
2 stops7h 57mAmerican Airlines
Fri 10/411:00 pmONT - STL
1 stop9h 04mAmerican Airlines
Deal found 4/26$448
Sat 9/289:50 amSTL - ONT
2 stops7h 57mAmerican Airlines
Fri 10/46:15 amONT - STL
2 stops8h 59mAmerican Airlines
Deal found 4/26$455
Thu 5/237:20 pmSTL - ONT
2 stops7h 07mAmerican Airlines
Mon 5/2711:59 pmONT - STL
1 stop7h 03mAmerican Airlines
Deal found 4/26$518
Sat 6/85:27 amSTL - ONT
1 stop6h 36mAmerican Airlines
Sat 6/812:49 pmONT - STL
1 stop5h 27mAmerican Airlines
Deal found 4/25$760
Sun 5/267:20 pmSTL - ONT
1 stop6h 36mAmerican Airlines
Sun 6/29:30 amONT - STL
2 stops7h 58mAmerican Airlines
Deal found 4/26$771

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 3,068,117 searches. Data last updated April 27, 2024.
Have a look at some of the cheapest available Frontier 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.
Sat 5/1811:41 pmSTL - ONT
1 stop8h 36mFrontier
Wed 5/225:41 pmONT - STL
1 stop14h 32mFrontier
Deal found 4/26$89
Sat 5/1811:41 pmSTL - ONT
1 stop8h 36mFrontier
Mon 5/209:57 pmONT - STL
1 stop10h 16mFrontier
Deal found 4/26$90
Fri 5/176:40 pmSTL - ONT
1 stop21h 55mFrontier
Tue 5/2112:59 amONT - STL
1 stop6h 37mFrontier
Deal found 4/26$99
Fri 5/178:45 pmSTL - ONT
1 stop12h 49mFrontier
Wed 5/2211:30 pmONT - STL
1 stop8h 43mFrontier
Deal found 4/26$100
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Sat 5/185:41 pmONT - STL
1 stop14h 32mFrontier
Deal found 4/26$103
Thu 5/167:23 pmSTL - ONT
1 stop16h 01mFrontier
Sun 5/1911:30 pmONT - STL
1 stop8h 43mFrontier
Deal found 4/26$110
Wed 5/88:04 pmSTL - ONT
1 stop5h 55mFrontier
Wed 5/1511:09 pmONT - STL
1 stop9h 04mFrontier
Deal found 4/26$112
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Sun 5/196:09 pmONT - STL
1 stop14h 04mFrontier
Deal found 4/26$113
Sat 5/1112:39 pmSTL - ONT
1 stop6h 20mFrontier
Mon 5/136:51 pmONT - STL
1 stop25h 08mFrontier
Deal found 4/26$117

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

Find cheap flight options from St. Louis to Ontario specifically for the months of April and May 2024. Explore affordable fares based on user searches. Over the last 7 days, Cheapflights users made 3,068,117 searches. Prices were last updated on April 27, 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.
Sat 5/1811:41 pmSTL - ONT
1 stop8h 36mFrontier
Wed 5/225:41 pmONT - STL
1 stop14h 32mFrontier
Deal found 4/26$89
Sat 5/1811:41 pmSTL - ONT
1 stop8h 36mFrontier
Mon 5/209:57 pmONT - STL
1 stop10h 16mFrontier
Deal found 4/26$90
Fri 5/176:40 pmSTL - ONT
1 stop21h 55mFrontier
Tue 5/2112:59 amONT - STL
1 stop6h 37mFrontier
Deal found 4/26$99
Fri 5/178:45 pmSTL - ONT
1 stop12h 49mFrontier
Wed 5/2211:30 pmONT - STL
1 stop8h 43mFrontier
Deal found 4/26$100
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Sat 5/185:41 pmONT - STL
1 stop14h 32mFrontier
Deal found 4/26$103
Thu 5/167:23 pmSTL - ONT
1 stop16h 01mFrontier
Sun 5/1911:30 pmONT - STL
1 stop8h 43mFrontier
Deal found 4/26$110
Wed 5/88:04 pmSTL - ONT
1 stop5h 55mFrontier
Wed 5/1511:09 pmONT - STL
1 stop9h 04mFrontier
Deal found 4/26$112
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Sun 5/196:09 pmONT - STL
1 stop14h 04mFrontier
Deal found 4/26$113
Sat 5/1112:39 pmSTL - ONT
1 stop6h 20mFrontier
Mon 5/136:51 pmONT - STL
1 stop25h 08mFrontier
Deal found 4/26$117

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 3,068,117 searches. Data last updated April 27, 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.
Sat 5/1811:41 pmSTL - ONT
1 stop8h 36mFrontier
Wed 5/225:41 pmONT - STL
1 stop14h 32mFrontier
Deal found 4/26$89
Sat 5/1811:41 pmSTL - ONT
1 stop8h 36mFrontier
Mon 5/209:57 pmONT - STL
1 stop10h 16mFrontier
Deal found 4/26$90
Fri 5/176:40 pmSTL - ONT
1 stop21h 55mFrontier
Tue 5/2112:59 amONT - STL
1 stop6h 37mFrontier
Deal found 4/26$99
Fri 5/178:45 pmSTL - ONT
1 stop12h 49mFrontier
Wed 5/2211:30 pmONT - STL
1 stop8h 43mFrontier
Deal found 4/26$100
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Sat 5/185:41 pmONT - STL
1 stop14h 32mFrontier
Deal found 4/26$103
Thu 5/167:23 pmSTL - ONT
1 stop16h 01mFrontier
Sun 5/1911:30 pmONT - STL
1 stop8h 43mFrontier
Deal found 4/26$110
Wed 5/88:04 pmSTL - ONT
1 stop5h 55mFrontier
Wed 5/1511:09 pmONT - STL
1 stop9h 04mFrontier
Deal found 4/26$112
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Sun 5/196:09 pmONT - STL
1 stop14h 04mFrontier
Deal found 4/26$113
Sat 5/1112:39 pmSTL - ONT
1 stop6h 20mFrontier
Mon 5/136:51 pmONT - STL
1 stop25h 08mFrontier
Deal found 4/26$117

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 3,068,117 searches. Data last updated April 27, 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.
Mon 5/68:04 pmSTL - ONT
1 stop12h 22mFrontier
Mon 5/1310:59 pmONT - STL
1 stop9h 10mFrontier
Deal found 4/26$152
Mon 5/68:04 pmSTL - ONT
1 stop12h 22mFrontier
Sat 5/118:01 pmONT - STL
1 stop12h 17mFrontier
Deal found 4/26$153
Mon 5/68:04 pmSTL - ONT
1 stop12h 22mFrontier
Tue 5/710:49 pmONT - STL
1 stop9h 29mFrontier
Deal found 4/27$160
Sun 5/510:59 pmSTL - ONT
1 stop24h 58mFrontier
Tue 5/712:39 pmONT - STL
1 stop19h 39mFrontier
Deal found 4/26$166
Sun 5/510:59 pmSTL - ONT
1 stop24h 58mFrontier
Mon 5/612:59 amONT - STL
1 stop12h 51mFrontier
Deal found 4/26$167
Fri 5/35:35 pmSTL - ONT
1 stop8h 20mFrontier
Sat 5/412:59 amONT - STL
1 stop11h 30mFrontier
Deal found 4/25$170
Fri 5/35:35 pmSTL - ONT
1 stop8h 20mFrontier
Sun 5/57:31 amONT - STL
1 stop24h 16mFrontier
Deal found 4/25$171
Thu 5/211:38 amSTL - ONT
1 stop20h 48mFrontier
Tue 5/712:39 pmONT - STL
1 stop19h 39mFrontier
Deal found 4/26$188
Mon 5/68:04 pmSTL - ONT
1 stop12h 22mFrontier
Sun 5/1212:59 amONT - STL
1 stop6h 48mFrontier
Deal found 4/26$196

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 3,068,117 searches. Data last updated April 27, 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.
Wed 5/88:04 pmSTL - ONT
1 stop5h 55mFrontier
Deal found 4/26$53
Thu 5/235:01 pmSTL - ONT
1 stop24h 38mFrontier
Deal found 4/26$55
Sat 5/118:04 pmSTL - ONT
1 stop5h 55mFrontier
Deal found 4/26$59
Mon 5/208:04 pmSTL - ONT
1 stop5h 55mFrontier
Deal found 4/26$72
Sun 5/1210:59 pmSTL - ONT
1 stop10h 04mFrontier
Deal found 4/26$75
Sat 5/412:39 pmSTL - ONT
1 stop6h 20mFrontier
Deal found 4/26$80
Fri 6/75:36 pmSTL - ONT
1 stop8h 06mFrontier
Deal found 4/26$81
Wed 6/58:02 pmSTL - ONT
1 stop5h 40mFrontier
Deal found 4/26$85
Tue 5/710:59 pmSTL - ONT
1 stop10h 09mFrontier
Deal found 4/26$86

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 3,068,117 searches. Data last updated April 27, 2024.

Fly from

Any airport

Fly to

Any airport

Budget

$89 - $398

Route

Depart

Return

Price

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Sat 5/18

1 stop8h 36m

Ontario

Wed 5/22

1 stop14h 32m

$89

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Sat 5/18

1 stop8h 36m

Ontario

Mon 5/20

1 stop10h 16m

$90

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Fri 5/17

1 stop21h 55m

Ontario

Tue 5/21

1 stop6h 37m

$99

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Fri 5/17

1 stop12h 49m

Ontario

Wed 5/22

1 stop8h 43m

$100

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Wed 5/15

1 stop7h 21m

Ontario

Sat 5/18

1 stop14h 32m

$103

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Thu 5/16

1 stop16h 01m

Ontario

Sun 5/19

1 stop8h 43m

$110

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Wed 5/8

1 stop5h 55m

Ontario

Wed 5/15

1 stop9h 04m

$112

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Wed 6/5

1 stop6h 18m

Ontario

Wed 6/12

1 stop5h 40m

$344

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Tue 10/22

1 stop9h 32m

Ontario

Sat 10/26

1 stop10h 36m

$398

Flights are sorted by cheapest first

Deals found on 4/26

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 January 28, 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 37 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 April 21, 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 $72 while a round-trip flight costs $161. Price data was last updated on April 21, 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 $346). 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

$270

February

$287

March

$281

April

$258

May

$271

June

$346

July

$335

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 April 27, 2024.
Peruse reviews from past customers who have flown with American Airlines, Frontier and United Airlines 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
9,115 reviews

Comfort

7.9

Boarding

8.2

Entertainment

7.3

Crew

8.6

Food

7.3

Overall

8.1

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
9,115 reviews
8.1
Very good
9,115 reviews

Comfort

7.9

Boarding

8.2

Entertainment

7.3

Crew

8.6

Food

7.3

Overall

8.1

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
10,966 reviews
8.1
Very good
9,115 reviews

Comfort

7.9

Boarding

8.2

Entertainment

7.3

Crew

8.6

Food

7.3

Overall

8.1

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
11,228 reviews
8.1
Very good
9,115 reviews

Comfort

7.9

Boarding

8.2

Entertainment

7.3

Crew

8.6

Food

7.3

Overall

8.1

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
14,889 reviews
8.1
Very good
9,115 reviews

Comfort

7.9

Boarding

8.2

Entertainment

7.3

Crew

8.6

Food

7.3

Overall

8.1

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
4,132 reviews
8.1
Very good
9,115 reviews

Comfort

7.9

Boarding

8.2

Entertainment

7.3

Crew

8.6

Food

7.3

Overall

8.1

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 $100 on Cheapflights?

    Yes, there are multiple flights from St. Louis to Ontario for under $100. The cheapest flight booked recently is on Frontier for just $89, but on average you can expect to pay $119.

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

    There are currently 17+ 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 $89, was found to be the cheapest airline from St. Louis to Ontario.. Frontier is priced at 75% 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 $53. However, be on the lookout for offers from Delta and American 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 4/26.

See more FAQs

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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 3,068,117 searches. Data last updated April 27, 2024.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$121Average$225FlexibilityNo cancel feeOn-time62%
Search Frontier flights
DeltaCheapest$286Average$426FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
American AirlinesCheapest$310Average$504FlexibilityNo 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.

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.

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