Cheap flights from St. Louis to Ontario (STL - ONT) from $46

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 5/1. 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
Apr 23 — Apr 301

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 18, 2024.

Popular in

June

Cheapest in

August

Round-trip from

$238

One-way from

$145
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 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 3,192,047 searches. Data last updated April 18, 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.
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Tue 5/2112:59 amONT - STL
1 stop6h 37mFrontier
Deal found 4/17$87
Sat 5/118:04 pmSTL - ONT
1 stop12h 27mFrontier
Mon 5/2012:59 amONT - STL
1 stop10h 10mFrontier
Deal found 4/17$89
Thu 5/910:59 pmSTL - ONT
1 stop10h 09mFrontier
Tue 5/146:55 pmONT - STL
1 stop13h 23mFrontier
Deal found 4/17$90
Thu 5/167:23 pmSTL - ONT
1 stop22h 16mFrontier
Tue 5/215:41 pmONT - STL
1 stop14h 32mFrontier
Deal found 4/18$100
Thu 5/165:01 pmSTL - ONT
1 stop24h 38mFrontier
Sun 5/196:09 pmONT - STL
1 stop14h 04mFrontier
Deal found 4/16$102
Wed 5/18:04 pmSTL - ONT
1 stop5h 55mFrontier
Tue 5/712:39 pmONT - STL
1 stop19h 39mFrontier
Deal found 4/18$104
Fri 5/178:45 pmSTL - ONT
1 stop12h 49mFrontier
Sun 5/1911:30 pmONT - STL
1 stop8h 43mFrontier
Deal found 4/17$110
Sat 5/188:04 pmSTL - ONT
1 stop5h 55mFrontier
Sat 5/2510:10 pmONT - STL
1 stop10h 03mFrontier
Deal found 4/17$111
Wed 5/18:04 pmSTL - ONT
1 stop5h 55mFrontier
Sat 5/412:59 amONT - STL
1 stop11h 30mFrontier
Deal found 4/17$114

Cheap Alaska Airlines flights from St. Louis to Ontario

Explore cheap flight options specifically provided by Alaska 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 3,192,047 searches. Data last updated April 18, 2024.
Have a look at some of the cheapest available Alaska 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.
Sat 6/17:41 pmSTL - ONT
1 stop15h 24mAlaska Airlines
Wed 6/57:10 amONT - STL
2 stops14h 49mAlaska Airlines
Deal found 4/17$482
Thu 5/97:00 amSTL - ONT
1 stop11h 05mAlaska Airlines
Tue 5/147:00 amONT - STL
2 stops14h 59mAlaska Airlines
Deal found 4/17$507
Wed 4/242:35 pmSTL - ONT
1 stop27h 30mAlaska Airlines
Sun 4/287:00 amONT - STL
2 stops14h 59mAlaska Airlines
Deal found 4/17$797

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 3,192,047 searches. Prices were last updated on April 18, 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.
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Tue 5/2112:59 amONT - STL
1 stop6h 37mFrontier
Deal found 4/17$87
Sat 5/118:04 pmSTL - ONT
1 stop12h 27mFrontier
Mon 5/2012:59 amONT - STL
1 stop10h 10mFrontier
Deal found 4/17$89
Thu 5/910:59 pmSTL - ONT
1 stop10h 09mFrontier
Tue 5/146:55 pmONT - STL
1 stop13h 23mFrontier
Deal found 4/17$90
Thu 5/167:23 pmSTL - ONT
1 stop22h 16mFrontier
Tue 5/215:41 pmONT - STL
1 stop14h 32mFrontier
Deal found 4/18$100
Thu 5/165:01 pmSTL - ONT
1 stop24h 38mFrontier
Sun 5/196:09 pmONT - STL
1 stop14h 04mFrontier
Deal found 4/16$102
Wed 5/18:04 pmSTL - ONT
1 stop5h 55mFrontier
Tue 5/712:39 pmONT - STL
1 stop19h 39mFrontier
Deal found 4/18$104
Fri 5/178:45 pmSTL - ONT
1 stop12h 49mFrontier
Sun 5/1911:30 pmONT - STL
1 stop8h 43mFrontier
Deal found 4/18$110
Sat 5/188:04 pmSTL - ONT
1 stop5h 55mFrontier
Sat 5/2510:10 pmONT - STL
1 stop10h 03mFrontier
Deal found 4/17$111
Wed 5/18:04 pmSTL - ONT
1 stop5h 55mFrontier
Sat 5/412:59 amONT - STL
1 stop11h 30mFrontier
Deal found 4/17$114

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 3,192,047 searches. Data last updated April 18, 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.
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Tue 5/2112:59 amONT - STL
1 stop6h 37mFrontier
Deal found 4/17$87
Sat 5/118:04 pmSTL - ONT
1 stop12h 27mFrontier
Mon 5/2012:59 amONT - STL
1 stop10h 10mFrontier
Deal found 4/17$89
Thu 5/910:59 pmSTL - ONT
1 stop10h 09mFrontier
Tue 5/146:55 pmONT - STL
1 stop13h 23mFrontier
Deal found 4/17$90
Thu 5/167:23 pmSTL - ONT
1 stop22h 16mFrontier
Tue 5/215:41 pmONT - STL
1 stop14h 32mFrontier
Deal found 4/18$100
Thu 5/165:01 pmSTL - ONT
1 stop24h 38mFrontier
Sun 5/196:09 pmONT - STL
1 stop14h 04mFrontier
Deal found 4/16$102
Wed 5/18:04 pmSTL - ONT
1 stop5h 55mFrontier
Tue 5/712:39 pmONT - STL
1 stop19h 39mFrontier
Deal found 4/18$104
Fri 5/178:45 pmSTL - ONT
1 stop12h 49mFrontier
Sun 5/1911:30 pmONT - STL
1 stop8h 43mFrontier
Deal found 4/18$110
Sat 5/188:04 pmSTL - ONT
1 stop5h 55mFrontier
Sat 5/2510:10 pmONT - STL
1 stop10h 03mFrontier
Deal found 4/17$111
Wed 5/18:04 pmSTL - ONT
1 stop5h 55mFrontier
Sat 5/412:59 amONT - STL
1 stop11h 30mFrontier
Deal found 4/17$114

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 3,192,047 searches. Data last updated April 18, 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.
Thu 4/2510:59 pmSTL - ONT
1 stop10h 09mFrontier
Thu 5/210:58 pmONT - STL
1 stop9h 20mFrontier
Deal found 4/18$119
Wed 4/248:04 pmSTL - ONT
1 stop12h 22mFrontier
Sat 4/2712:59 amONT - STL
1 stop11h 30mFrontier
Deal found 4/17$136
Wed 4/248:04 pmSTL - ONT
1 stop12h 22mFrontier
Wed 5/110:49 pmONT - STL
1 stop9h 29mFrontier
Deal found 4/17$158
Tue 4/234:50 pmSTL - ONT
1 stop9h 09mFrontier
Tue 4/3010:49 pmONT - STL
1 stop9h 29mFrontier
Deal found 4/17$169
Wed 4/248:04 pmSTL - ONT
1 stop12h 22mFrontier
Sun 4/2812:29 pmONT - STL
1 stop7h 28mFrontier
Deal found 4/17$185
Thu 4/2510:59 pmSTL - ONT
1 stop10h 09mFrontier
Wed 5/112:59 amONT - STL
1 stop7h 39mFrontier
Deal found 4/18$209
Wed 4/2410:20 amSTL - ONT
2 stops14h 20mDelta
Wed 5/15:19 pmONT - STL
1 stop5h 19mDelta
Deal found 4/17$536
Thu 4/258:47 amSTL - ONT
2 stops16h 17mUnited Airlines
Thu 5/21:36 pmONT - STL
1 stop5h 43mUnited Airlines
Deal found 4/18$580
Wed 4/249:30 amSTL - ONT
2 stops11h 19mAmerican Airlines
Wed 5/16:25 amONT - STL
2 stops9h 22mAmerican Airlines
Deal found 4/17$592

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 3,192,047 searches. Data last updated April 18, 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 5/18:04 pmSTL - ONT
1 stop5h 55mFrontier
Deal found 4/18$46
Mon 5/208:04 pmSTL - ONT
1 stop5h 55mFrontier
Deal found 4/17$48
Tue 5/710:59 pmSTL - ONT
1 stop10h 09mFrontier
Deal found 4/16$51
Sat 5/412:39 pmSTL - ONT
1 stop6h 20mFrontier
Deal found 4/17$59
Fri 5/178:45 pmSTL - ONT
1 stop12h 49mFrontier
Deal found 4/17$61
Tue 5/74:50 pmSTL - ONT
1 stop9h 09mFrontier
Deal found 4/17$65
Thu 4/2510:59 pmSTL - ONT
1 stop10h 09mFrontier
Deal found 4/17$66
Mon 5/67:51 pmSTL - ONT
1 stop13h 12mFrontier
Deal found 4/16$69
Sun 5/510:59 pmSTL - ONT
1 stop24h 58mFrontier
Deal found 4/18$79

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 3,192,047 searches. Data last updated April 18, 2024.

Fly from

Any airport

Fly to

Any airport

Budget

$87 - $357

Route

Depart

Return

Price

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Wed 5/15

1 stop7h 21m

Ontario

Tue 5/21

1 stop6h 37m

$87

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Sat 5/11

1 stop12h 27m

Ontario

Mon 5/20

1 stop10h 10m

$89

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Thu 5/9

1 stop10h 09m

Ontario

Tue 5/14

1 stop13h 23m

$90

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Thu 5/16

1 stop22h 16m

Ontario

Tue 5/21

1 stop14h 32m

$100

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Thu 5/16

1 stop24h 38m

Ontario

Sun 5/19

1 stop14h 04m

$102

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Wed 5/1

1 stop5h 55m

Ontario

Tue 5/7

1 stop19h 39m

$104

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Fri 5/17

1 stop12h 49m

Ontario

Sun 5/19

1 stop8h 43m

$110

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Wed 6/5

1 stop6h 18m

Ontario

Tue 6/11

1 stop5h 40m

$344

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Sun 5/5

1 stop10h 04m

Ontario

Wed 5/8

2 stops14h 59m

$357

Flights are sorted by cheapest first

Deals found on 4/17

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 14, 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 $60 while a round-trip flight costs $154. Price data was last updated on April 14, 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

$268

May

$274

June

$346

July

$335

August

$287

September

$257

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 18, 2024.
Peruse reviews from past customers who have flown with Frontier, Alaska Airlines 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
9,106 reviews

Food

7.3

Boarding

8.2

Overall

8.1

Crew

8.6

Comfort

7.9

Entertainment

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
9,106 reviews
8.1
Very good
9,106 reviews

Food

7.3

Boarding

8.2

Overall

8.1

Crew

8.6

Comfort

7.9

Entertainment

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
11,104 reviews
8.1
Very good
9,106 reviews

Food

7.3

Boarding

8.2

Overall

8.1

Crew

8.6

Comfort

7.9

Entertainment

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
11,341 reviews
8.1
Very good
9,106 reviews

Food

7.3

Boarding

8.2

Overall

8.1

Crew

8.6

Comfort

7.9

Entertainment

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
14,963 reviews
8.1
Very good
9,106 reviews

Food

7.3

Boarding

8.2

Overall

8.1

Crew

8.6

Comfort

7.9

Entertainment

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
4,168 reviews
8.1
Very good
9,106 reviews

Food

7.3

Boarding

8.2

Overall

8.1

Crew

8.6

Comfort

7.9

Entertainment

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 $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 $87, but on average you can expect to pay $114.

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

    There are currently 10+ 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 $87, was found to be the cheapest airline from St. Louis to Ontario.. Frontier is priced at 76% 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 $46. However, be on the lookout for offers from United Airlines and Delta, 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 4/18.

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 3,192,047 searches. Data last updated April 18, 2024.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$125Average$224FlexibilityNo cancel feeOn-time62%
Search Frontier flights
DeltaCheapest$286Average$426FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
American AirlinesCheapest$309Average$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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