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$68+ Cheap flights from Ontario to St. Louis (ONT - STL)

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 10/18. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — STL
Jul 30 — Aug 61
From?
To?
Tue 7/30
Tue 8/6
1 adult, Economy
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The best prices from Ontario to Lambert-St Louis are usually found in June or October, booked 53 days in advance, depart on a Saturday or Monday and return on a Monday

Cheap flight deals from Ontario to St. Louis

Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) to St. Louis (STL). 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 July 25, 2024.

Popular in

December

Cheapest in

June

Round-trip from

$131
(FlightNetwork)

One-way from

$68
(mytrip.com)
High demand for flights, 42% potential price rise
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Best time to find cheap flights, 33% potential price drop
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From Ontario to Lambert-St Louis
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One-way flight from Ontario to Lambert-St Louis
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What is the cheapest day to fly round-trip from Ontario to St. Louis?

Leaving on a Friday is a viable option for saving on travel. Heavily demanded days of the week can typically drive up the prices you see. Booking your travel for a less competitive day can save up to 77% on the overall cost on flights from Ontario to St. Louis.

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

Users have found that booking a flight from Ontario to St. Louis at least 48 days early can save you up to 79% on average compared to booking a flight this week. If booking 48 days before your flight isn’t an option for you, users have found flights from Ontario to St. Louis for as little as $456 when booking for a departure date within the next two weeks. You can also check prices now. Some users have found airline tickets as low as $581 for flights departing within the next 3 days.

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

The best pricing can be found in the month of January. Prices to St. Louis from Ontario average $404. You can even find prices in January for less than $404, as users have found deals to St. Louis from as low as $215. The month of June appears to be one of the more expensive times to travel to St. Louis from Ontario. Flying in the targeted month can save you up to 11%.

What is the cheapest time of day to fly from ONT to STL?

A simple way to save on the total cost of your ticket is to fly from Ontario to St. Louis in the evening. If you’re flexible enough to do this you can expect to save up to 59% on your trip compared to booking a flight in the afternoon.

Cheap Ontario to St. Louis flights in July & August 2024

Find cheap flight options from Ontario to St. Louis specifically for the months of July and August 2024. Explore affordable fares based on user searches. Over the last 7 days, Cheapflights users made 2,752,877 searches. Prices were last updated on July 25, 2024.
These are some of the most attractive deals on flights from Ontario to St. Louis in 2024. More deals are always being added, so be sure to check back regularly.
This FlightNetwork deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightNetwork is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/2112:49 amONT - STL
1 stop15h 59mFrontier
Thu 8/2911:12 pmSTL - ONT
1 stop11h 01mFrontier
Deal found 7/24$132
This mytrip.com deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/2112:49 amONT - STL
1 stop15h 59mFrontier
Mon 8/269:24 pmSTL - ONT
1 stop28h 35mFrontier
Deal found 7/25$133
This mytrip.com deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/2710:07 pmONT - STL
1 stop21h 15mFrontier
Tue 9/175:30 pmSTL - ONT
1 stop18h 11mFrontier
Deal found 7/25$137
This mytrip.com deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/1312:59 amONT - STL
1 stop15h 49mFrontier
Wed 8/2810:22 pmSTL - ONT
1 stop10h 41mFrontier
Deal found 7/24$138
This mytrip.com deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/1412:49 amONT - STL
1 stop15h 59mFrontier
Mon 8/193:15 pmSTL - ONT
1 stop11h 08mFrontier
Deal found 7/24$139
This Frontier deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/166:00 amONT - STL
1 stop5h 55mFrontier
Sun 8/1811:12 pmSTL - ONT
1 stop11h 01mFrontier
Deal found 7/24$140
This mytrip.com deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/1710:59 pmONT - STL
1 stop21h 13mFrontier
Tue 8/207:48 pmSTL - ONT
1 stop13h 29mFrontier
Deal found 7/25$141
This mytrip.com deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/166:00 amONT - STL
1 stop5h 55mFrontier
Sun 8/1811:12 pmSTL - ONT
1 stop11h 01mFrontier
Deal found 7/25$142
This mytrip.com deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/166:00 amONT - STL
1 stop5h 55mFrontier
Sun 8/1811:12 pmSTL - ONT
1 stop11h 01mFrontier
Deal found 7/24$143

Ontario to St. Louis 2024 flight deals

Discover exclusive flight deals for travel between Ontario and St. Louis in 2024. Find excellent offers based on user searches. Over the last 7 days, Cheapflights users made 2,752,877 searches. Data last updated July 25, 2024.
These are some of the most attractive deals on flights from Ontario to St. Louis in 2024. More deals are always being added, so be sure to check back regularly.
This FlightNetwork deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightNetwork is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/11:35 pmONT - STL
1 stop6h 37mFrontier
Sat 9/75:20 pmSTL - ONT
1 stop8h 39mFrontier
Deal found 7/24$131
This FlightNetwork deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightNetwork is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/2112:49 amONT - STL
1 stop15h 59mFrontier
Thu 8/2911:12 pmSTL - ONT
1 stop11h 01mFrontier
Deal found 7/24$132
This mytrip.com deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/41:31 pmONT - STL
1 stop5h 51mFrontier
Wed 9/115:20 pmSTL - ONT
1 stop8h 39mFrontier
Deal found 7/25$133
This mytrip.com deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/56:30 amONT - STL
1 stop14h 49mFrontier
Mon 9/910:55 pmSTL - ONT
1 stop15h 37mFrontier
Deal found 7/25$136
This mytrip.com deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/2710:07 pmONT - STL
1 stop21h 15mFrontier
Tue 9/175:30 pmSTL - ONT
1 stop18h 11mFrontier
Deal found 7/25$137
This mytrip.com deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/1312:59 amONT - STL
1 stop15h 49mFrontier
Wed 8/2810:22 pmSTL - ONT
1 stop10h 41mFrontier
Deal found 7/24$138
This mytrip.com deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/1412:49 amONT - STL
1 stop15h 59mFrontier
Mon 8/193:15 pmSTL - ONT
1 stop11h 08mFrontier
Deal found 7/24$139
This Frontier deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/166:00 amONT - STL
1 stop5h 55mFrontier
Tue 8/209:36 pmSTL - ONT
1 stop12h 37mFrontier
Deal found 7/25$140
This mytrip.com deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/1710:59 pmONT - STL
1 stop21h 13mFrontier
Tue 8/207:48 pmSTL - ONT
1 stop13h 29mFrontier
Deal found 7/25$141

Ontario to St. Louis flights leaving soon

Find last-minute flight options from Ontario to St. Louis 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 2,752,877 searches. Data last updated July 25, 2024.
Have a look at some of the flights available from Ontario to St. Louis departing last-minute. Tip: verify your flight details before completing your reservation.
This mytrip.com deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/49:10 pmONT - STL
1 stop12h 12mFrontier
Fri 8/167:48 pmSTL - ONT
1 stop5h 51mFrontier
Deal found 7/24$168
This Frontier deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/110:31 pmONT - STL
1 stop11h 15mFrontier
Thu 8/1511:12 pmSTL - ONT
1 stop11h 01mFrontier
Deal found 7/24$170
This mytrip.com deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/412:54 pmONT - STL
1 stop6h 37mFrontier
Tue 8/207:48 pmSTL - ONT
1 stop13h 29mFrontier
Deal found 7/24$176
This mytrip.com deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/412:54 pmONT - STL
1 stop6h 37mFrontier
Thu 8/1511:12 pmSTL - ONT
1 stop11h 01mFrontier
Deal found 7/24$177
This mytrip.com deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/17:21 pmONT - STL
1 stop24h 10mFrontier
Sat 8/178:55 pmSTL - ONT
1 stop12h 08mFrontier
Deal found 7/24$181
This mytrip.com deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/28:36 pmONT - STL
1 stop18h 02mFrontier
Thu 8/1511:12 pmSTL - ONT
1 stop11h 01mFrontier
Deal found 7/24$182
This mytrip.com deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/310:30 pmONT - STL
1 stop21h 01mFrontier
Thu 8/1511:12 pmSTL - ONT
1 stop11h 01mFrontier
Deal found 7/24$183
This Gotogate deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/47:10 pmONT - STL
1 stop14h 12mFrontier
Wed 8/710:32 pmSTL - ONT
1 stop17h 57mFrontier
Deal found 7/24$186
This Frontier deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/49:10 pmONT - STL
1 stop12h 12mFrontier
Sun 8/1110:46 pmSTL - ONT
1 stop12h 12mFrontier
Deal found 7/24$194

One-way flights to St. Louis from Ontario

Search for one-way flight options from Ontario to St. Louis. 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 2,752,877 searches. Data last updated July 25, 2024.
Users in need of a one-way flight from Ontario to St. Louis can choose from these deals. Users in need of a round-trip flight from Ontario to St. Louis instead should update the search form at the top of page.
This mytrip.com deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/1812:49 amONT - STL
1 stop6h 48mFrontier
Deal found 7/24$68
This mytrip.com deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/251:35 pmONT - STL
1 stop6h 37mFrontier
Deal found 7/24$69
This mytrip.com deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/236:00 amONT - STL
1 stop5h 55mFrontier
Deal found 7/24$70
This mytrip.com deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/236:30 amONT - STL
1 stop5h 56mFrontier
Deal found 7/25$72
This mytrip.com deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/1510:07 pmONT - STL
1 stop11h 40mFrontier
Deal found 7/24$74
This mytrip.com deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/2212:59 amONT - STL
1 stop15h 49mFrontier
Deal found 7/24$75
This Frontier deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/238:35 pmONT - STL
1 stop11h 43mFrontier
Deal found 7/24$76
This Frontier deal was found by Cheapflights users on 7/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/151:35 pmONT - STL
1 stop6h 37mFrontier
Deal found 7/23$77
This mytrip.com deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure mytrip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/28:15 pmONT - STL
1 stop22h 21mFrontier
Deal found 7/25$78

Find flights from Ontario to St. Louis within your budget

Customize your flight search to find flights from Ontario to St. Louis 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 2,752,877 searches. Data last updated July 25, 2024.

Fly from

Any airport

Fly to

Any airport

Budget

$131 - $357

Route

Depart

Return

Price

OntarioLambert-St Louis

ONT - STL

ONTSTL

Ontario

Sun 9/1

1 stop6h 37m

Lambert-St Louis

Sat 9/7

1 stop8h 39m

$131

OntarioLambert-St Louis

ONT - STL

ONTSTL

Ontario

Wed 8/21

1 stop15h 59m

Lambert-St Louis

Thu 8/29

1 stop11h 01m

$132

OntarioLambert-St Louis

ONT - STL

ONTSTL

Ontario

Wed 8/28

1 stop5h 51m

Lambert-St Louis

Tue 9/3

1 stop6h 11m

$133

OntarioLambert-St Louis

ONT - STL

ONTSTL

Ontario

Sun 9/15

1 stop22h 48m

Lambert-St Louis

Tue 9/24

1 stop18h 11m

$136

OntarioLambert-St Louis

ONT - STL

ONTSTL

Ontario

Tue 10/1

2 stops15h 32m

Lambert-St Louis

Sat 10/5

1 stop8h 39m

$267

OntarioLambert-St Louis

ONT - STL

ONTSTL

Ontario

Sat 9/14

1 stop5h 35m

Lambert-St Louis

Tue 9/24

2 stops12h 45m

$330

OntarioLambert-St Louis

ONT - STL

ONTSTL

Ontario

Wed 8/14

1 stop5h 39m

Lambert-St Louis

Wed 8/28

2 stops9h 54m

$331

OntarioLambert-St Louis

ONT - STL

ONTSTL

Ontario

Sat 8/17

2 stops8h 37m

Lambert-St Louis

Tue 8/20

2 stops7h 36m

$346

OntarioLambert-St Louis

ONT - STL

ONTSTL

Ontario

Wed 8/28

2 stops23h 55m

Lambert-St Louis

Tue 9/3

1 stop28h 15m

$357

Flights are sorted by cheapest first

Deals found on 7/24

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

Use this chart to determine the optimal time to book a round-trip flight from Ontario to St. Louis. Price data was last updated on July 23, 2024.
The best time to book flights from Ontario to St. Louis is 53 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.
Search Deals

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

Use this chart to determine the cheapest time to fly round-trip from Ontario to St. Louis. Price data was last updated on July 21, 2024.
Morning
Noon
Afternoon
Evening
All times are departure.
Travelers seeking maximum savings on their Ontario to St. Louis flight should consider departing on Saturday afternoons when fares are most often at their lowest. Monday mornings flights should be avoided if possible as fares are typically the most expensive at this time.
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Best time to book a flight from Ontario to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Ontario with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Temperature and rainfall in St. Louis by month

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

STL

Temperature

32 - 80.6 °F

If weather is an important factor for your trip to St. Louis, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 80.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 32.0 F).

Reviews of airlines servicing St. Louis

Get insights into the airlines that provide service to St. Louis. 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 St. Louis. Reviews last updated July 25, 2024.
Read through reviews of airlines operating flights from Ontario to St. Louis, such as United Airlines, Frontier and Alaska Airlines. In addition to providing an overall rating, users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.1
Very good
9,365 reviews

Overall

8.1

Entertainment

7.2

Comfort

7.9

Food

7.2

Boarding

8.2

Crew

8.6

Reviews

1 / 10

Paid a lot for our exit row seats and they weren’t that roomy.

Alaska Airlines
8.1
Very good
9,365 reviews
Alaska Airlines
8.1
Very good
9,365 reviews

Overall

8.1

Entertainment

7.2

Comfort

7.9

Food

7.2

Boarding

8.2

Crew

8.6

Reviews

1 / 10

Paid a lot for our exit row seats and they weren’t that roomy.

Delta
8.0
Very good
9,630 reviews
Alaska Airlines
8.1
Very good
9,365 reviews

Overall

8.1

Entertainment

7.2

Comfort

7.9

Food

7.2

Boarding

8.2

Crew

8.6

Reviews

1 / 10

Paid a lot for our exit row seats and they weren’t that roomy.

United Airlines
7.4
Good
10,000 reviews
Alaska Airlines
8.1
Very good
9,365 reviews

Overall

8.1

Entertainment

7.2

Comfort

7.9

Food

7.2

Boarding

8.2

Crew

8.6

Reviews

1 / 10

Paid a lot for our exit row seats and they weren’t that roomy.

American Airlines
7.3
Good
10,000 reviews
Alaska Airlines
8.1
Very good
9,365 reviews

Overall

8.1

Entertainment

7.2

Comfort

7.9

Food

7.2

Boarding

8.2

Crew

8.6

Reviews

1 / 10

Paid a lot for our exit row seats and they weren’t that roomy.

Avianca
7.3
Good
3,352 reviews
Alaska Airlines
8.1
Very good
9,365 reviews

Overall

8.1

Entertainment

7.2

Comfort

7.9

Food

7.2

Boarding

8.2

Crew

8.6

Reviews

1 / 10

Paid a lot for our exit row seats and they weren’t that roomy.

Related info for your journey

Find useful and relevant information for your journey from Ontario to St. Louis. 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 Ontario to St. Louis for under $200 on Cheapflights?

    Yes, there are multiple flights from Ontario to St. Louis for under $200. The cheapest flight booked recently is on Frontier for just $131, but on average you can expect to pay $143.

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

    There are currently 20+ open flights from Ontario to St. Louis within the next 7 days for less than $200.

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

    Flying on Frontier is currently your cheapest option to St. Louis, with prices starting at $131. Frontier is priced at 59% lower than the current average price of a flight leaving 3 months from now.

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

    The cheapest airlines for a one-way flight from Ontario to St. Louis are Frontier ($68), Delta ($163), and Alaska Airlines ($186).

  • What does ONT to STL mean?

    These are just IATA (International Air Transport Association) codes. They are used in aviation to identify and differentiate airports. That’s why a Ontario Airport to Lambert-St Louis Airport flight would often be abbreviated as a ONT to STL flight.

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

    The amount of baggage you can bring on your Ontario to St. Louis 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 Ontario to St. Louis with specific airlines?

    Yes, Cheapflights allows you to browse and filter Ontario to St. Louis 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 Ontario to St. Louis that include hotel bookings?

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

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

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

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

    Yes. Cheapflights offers flight deals from Ontario to St. Louis 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 Ontario to St. Louis that allow pets onboard?

    Many airlines flying from Ontario to St. Louis 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 Ontario to St. Louis?

    Yes, you can often find last-minute deals on Ontario to St. Louis 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 Ontario to St. Louis flight deals updated?

    The Ontario to St. Louis flight deals you see on this page were last updated on 7/25.

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

    Before booking your flight from Ontario to St. Louis check out the most popular airlines for this route: American Airlines, Delta or Frontier.

  • What is the cheapest month to book a flight from Ontario to St. Louis?

    Currently, September is the cheapest month in which you can book a flight from Ontario to St. Louis (average of $312). Flying from Ontario to St. Louis in March is currently the most expensive (average of $357). 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.

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Top 4 airlines flying from Ontario to St. Louis

Discover the top 4 airlines that operate flights from Ontario to St. Louis. 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 2,752,877 searches. Data last updated July 25, 2024.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$102Average$189FlexibilityNo cancel feeOn-time62%
DeltaCheapest$276Average$379FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$282Average$464FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$288Average$487FlexibilityNo cancel feeOn-time69%
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Search flights from Ontario to St. Louis by cabin class

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

Find hourly flight availability from Ontario to St. Louis. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated July 25, 2024.
0%of flight departuresEarly morningMidnight to 6 am
100%of flight departuresMorning6 am to noon
0%of flight departuresAfternoonNoon to 6 pm
0%of flight departuresEvening6 pm to midnight
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