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$62+ Cheap flights from Missouri to Ontario (ONT)

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 1/24. Fares are subject to change and may not be available on all flights or dates of travel.
STL — ONT
Jan 27 — Feb 31
Tue 1/27
Tue 2/3
1 adult, Economy
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Cheap flight deals from Missouri to Ontario

Cheapest flights from Missouri to Ontario
Explore the most affordable flight options available from Missouri to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on December 28, 2025.

This CheapOair deal was found by Cheapflights users on 12/25. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/2810:10 pmSTL - ONT
1 stop21h 05mFrontier
Sat 1/179:10 pmONT - STL
1 stop22h 04mFrontier
Deal found 12/25$363
This Frontier deal was found by Cheapflights users on 12/26. 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 12/318:45 pmMCI - ONT
1 stop5h 14mFrontier
Sun 1/116:00 amONT - MCI
1 stop11h 26mFrontier
Deal found 12/26$367
This Expedia deal was found by Cheapflights users on 12/26. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/297:43 pmSTL - ONT
1 stop6h 16mFrontier
Mon 1/56:00 amONT - STL
1 stop13h 25mFrontier
Deal found 12/26$413
This CheapOair deal was found by Cheapflights users on 12/26. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/2810:10 pmSTL - ONT
1 stop25h 07mFrontier
Sun 1/46:37 pmONT - STL
1 stop24h 48mFrontier
Deal found 12/26$438
This Booking.com deal was found by Cheapflights users on 12/26. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/318:45 pmMCI - ONT
1 stop5h 14mFrontier
Sat 1/36:45 amONT - MCI
1 stop11h 06mFrontier
Deal found 12/26$442
This Gotogate deal was found by Cheapflights users on 12/26. 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.
Mon 12/298:45 pmMCI - ONT
1 stop5h 14mFrontier
Sat 1/36:45 amONT - MCI
1 stop11h 06mFrontier
Deal found 12/26$470
This American Airlines deal was found by Cheapflights users on 12/26. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/3010:31 amSGF - ONT
2 stops9h 57mAmerican Airlines
Thu 1/12:42 pmONT - SGF
1 stop7h 14mAmerican Airlines
Deal found 12/26$474
This Frontier deal was found by Cheapflights users on 12/26. 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 12/315:19 pmSTL - ONT
1 stop5h 58mFrontier
Thu 1/16:00 amONT - STL
1 stop8h 24mFrontier
Deal found 12/26$482
This CheapOair deal was found by Cheapflights users on 12/26. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/3010:10 pmSTL - ONT
1 stop21h 05mFrontier
Thu 1/16:00 amONT - STL
1 stop8h 24mFrontier
Deal found 12/26$483
This CheapOair deal was found by Cheapflights users on 12/26. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/2810:10 pmSTL - ONT
1 stop25h 07mFrontier
Tue 12/306:00 amONT - STL
1 stop13h 25mFrontier
Deal found 12/26$503
This Gotogate deal was found by Cheapflights users on 12/26. 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.
Tue 12/3010:10 pmSTL - ONT
1 stop21h 05mFrontier
Fri 1/26:45 amONT - STL
1 stop25h 17mFrontier
Deal found 12/26$512
This Frontier deal was found by Cheapflights users on 12/25. 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.
Sun 12/288:45 pmMCI - ONT
1 stop5h 14mFrontier
Sat 1/36:45 amONT - MCI
1 stop11h 06mFrontier
Deal found 12/25$512

Find flight deals from Missouri to Ontario

Keep the following information in mind while searching for Missouri to Ontario flight deals. Data was last updated December 28, 2025.

Most accurate provider

Justfly.com
3 stars

Most trusted provider

Justfly.com
3 stars

Round-trip from

$148
(Frontier)

One-way from

$62
(Trip.com)

Popular in

March

Cheapest in

September

Average price

$422
Provider with most accurate pricing for Lambert-St Louis-Los Angeles flight deals.
Search Deals
Provider most trusted by Cheapflights users for Lambert-St Louis-Los Angeles flights.
Search Deals
From Missouri to Ontario
Search Deals
One-way flight from Missouri to Ontario
Search Deals
Highest demand for flights based on searches. 2% potential increase in price ($11 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($5 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in December 2025
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Missouri 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 2,558,603 searches. Data last updated December 28, 2025.
Use the filters below to find and compare flights from Missouri to Ontario that are best for you.

Fly from

Missouri

Fly to

Ontario

Route

Depart

Return

Price

St. LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Wed 2/11

3:28 pm-9:34 am

1 stop20h 06m

Ontario

Wed 2/25

7:17 pm-9:26 pm

1 stop24h 09m

$165

St. LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Thu 1/29

10:01 pm-9:23 am

1 stop13h 22m

Ontario

Mon 2/2

1:05 pm-8:50 pm

1 stop5h 45m

$182

Kansas CityOntario

MCI - ONT

MCIONT

Kansas City

Sun 1/25

8:41 pm-12:20 am

1 stop5h 39m

Ontario

Sun 2/1

6:20 am-7:51 pm

1 stop11h 31m

$200

St. LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Sat 1/24

3:46 pm-11:24 pm

1 stop9h 38m

Ontario

Sat 1/31

7:15 am-2:46 pm

1 stop5h 31m

$220

Kansas CityOntario

MCI - ONT

MCIONT

Kansas City

Mon 2/2

8:41 pm-1:37 pm

2 stops18h 56m

Ontario

Fri 2/6

6:20 am-7:51 pm

1 stop11h 31m

$220

St. LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Sat 3/7

8:12 pm-12:01 am

1 stop5h 49m

Ontario

Tue 3/10

4:49 pm-11:19 am

1 stop16h 30m

$221

Kansas CityOntario

MCI - ONT

MCIONT

Kansas City

Thu 2/19

7:00 am-1:11 pm

1 stop8h 11m

Ontario

Sun 2/22

10:18 pm-7:48 pm

2 stops19h 30m

$233

St. LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Sat 1/17

3:43 pm-10:59 pm

1 stop9h 16m

Ontario

Sun 1/18

10:18 pm-12:40 pm

1 stop12h 22m

$268

St. LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Sun 1/11

12:37 pm-4:20 pm

1 stop5h 43m

Ontario

Sun 1/18

10:18 pm-12:40 pm

1 stop12h 22m

$272

Kansas CityOntario

MCI - ONT

MCIONT

Kansas City

Wed 2/11

5:48 pm-9:34 pm

1 stop5h 46m

Ontario

Wed 2/18

7:30 am-3:44 pm

1 stop6h 14m

$273

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/25

Showing 1-10 of 60 results
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Best time to book a flight from Missouri to Ontario

Have a flexible travel schedule? Discover the best time to fly to Ontario from Missouri 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.

Cheapflights Insights

Everything you need to know about your flight from Missouri to Ontario

What is the cheapest month to book a flight from Missouri to Ontario?

Currently, November is the cheapest month in which you can book a flight from Missouri to Ontario (average of $67). Flying from Missouri to Ontario in December is currently the most expensive (average of $124). 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.

Related info for your journey

Find useful and relevant information for your journey from Missouri to Ontario. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to Ontario from Missouri?

    For a flight from Missouri to Ontario, you will be flying into Ontario. Ontario (ONT) is just 3.1 mi from the center of the city.

  • How long is the flight from Missouri to Ontario?

    For as low as $338, Frontier can have you in Ontario from Missouri in 6h 02m. The distance from Missouri to Ontario is about 1442 mi. This flight may include one or multiple stops.

  • What are the most popular routes from Missouri to Ontario?

    When deciding which route to take from Missouri to Ontario consider Lambert-St Louis - Ontario, Kansas City - Ontario or Springfield-Branson - Ontario as they are the most popular.

  • Can I find deals for flights from Missouri to Ontario that include hotel bookings?

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

  • How can I find direct flights from Missouri to Ontario?

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

  • Can I find deals for business class flights from Missouri to Ontario?

    Yes. Cheapflights offers flight deals from Missouri 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.

  • What is the cheapest month to book a flight from Missouri to Ontario?

    Currently, November is the cheapest month in which you can book a flight from Missouri to Ontario (average of $67). Flying from Missouri to Ontario in December is currently the most expensive (average of $124). 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.

See more FAQs

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Alternative routes for Missouri to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
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Top 5 airlines flying from Missouri to Ontario

Discover the top 5 airlines that operate flights from Missouri 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 2,558,603 searches. Data last updated December 28, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$75Average$230FlexibilityNo cancel feeOn-time62%
DeltaCheapest$171Average$362FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$264Average$422FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$284Average$427FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$289Average$394FlexibilityNo cancel feeOn-time63%

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