HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Missouri

$72+ Cheap flights from Ontario (ONT) to Missouri

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 9/3. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — STL
Aug 25 — Sep 11
Mon 8/25
Mon 9/1
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Ontario to Missouri with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheap flight deals from Ontario to Missouri

Keep the following information in mind while searching for Ontario to Missouri flight deals. Data was last updated August 20, 2025.

Round-trip from

$142
(Gotogate)

One-way from

$72
(Mytrip)

Popular in

February

Cheapest in

September

Average price

$269
From Ontario to Missouri
Search Deals
One-way flight from Ontario to Missouri
Search Deals
Highest demand for flights based on searches. 10% potential increase in price ($34 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($6 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in August 2025
Search Deals

Find flight deals from Ontario to Missouri

Cheapest flights from Ontario to Missouri
Explore the most affordable flight options available from Ontario to Missouri. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 20, 2025.

This Gotogate deal was found by Cheapflights users on 8/18. 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 9/212:59 amONT - STL
1 stop6h 12mFrontier
Sun 9/77:55 pmSTL - ONT
1 stop25h 59mFrontier
Deal found 8/18$142
This Mytrip deal was found by Cheapflights users on 8/18. 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 is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/212:59 amONT - STL
1 stop6h 12mFrontier
Mon 9/87:55 pmSTL - ONT
1 stop25h 59mFrontier
Deal found 8/18$143
This Booking.com deal was found by Cheapflights users on 8/18. 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.
Thu 9/43:43 pmONT - STL
1 stop15h 23mFrontier
Mon 9/87:55 pmSTL - ONT
1 stop25h 59mFrontier
Deal found 8/18$144
This Priceline deal was found by Cheapflights users on 8/18. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/612:05 pmONT - MCI
1 stop5h 28mFrontier
Sun 11/98:28 pmMCI - ONT
1 stop5h 22mFrontier
Deal found 8/18$144
This Mytrip deal was found by Cheapflights users on 8/18. 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 is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/88:59 pmONT - STL
1 stop10h 07mFrontier
Sun 9/1410:39 amSTL - ONT
1 stop9h 36mFrontier
Deal found 8/18$148
This Booking.com deal was found by Cheapflights users on 8/18. 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.
Fri 9/128:59 pmONT - STL
1 stop10h 07mFrontier
Sun 9/1410:39 amSTL - ONT
1 stop6h 45mFrontier
Deal found 8/18$149
This Mytrip deal was found by Cheapflights users on 8/18. 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 is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/38:00 amONT - STL
1 stop27h 53mFrontier
Fri 9/57:55 pmSTL - ONT
1 stop25h 59mFrontier
Deal found 8/18$150
This Booking.com deal was found by Cheapflights users on 8/18. 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.
Fri 10/34:08 pmONT - STL
1 stop14h 58mFrontier
Mon 10/69:29 pmSTL - ONT
1 stop25h 13mFrontier
Deal found 8/18$151
This Mytrip deal was found by Cheapflights users on 8/19. 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 is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/910:05 amONT - STL
1 stop23h 38mFrontier
Sat 10/117:52 pmSTL - ONT
1 stop5h 58mFrontier
Deal found 8/19$155
This Priceline deal was found by Cheapflights users on 8/18. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/67:39 amONT - STL
1 stop7h 48mFrontier
Sun 11/92:42 pmSTL - ONT
1 stop9h 23mFrontier
Deal found 8/18$156
This Cheapflightsfares deal was found by Cheapflights users on 8/17. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/316:00 amONT - STL
1 stop5h 57mFrontier
Sun 11/27:45 pmSTL - ONT
1 stop6h 05mFrontier
Deal found 8/17$157
This Frontier deal was found by Cheapflights users on 8/17. 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.
Tue 9/212:59 amONT - STL
1 stop6h 12mFrontier
Thu 9/1110:49 amSTL - ONT
1 stop6h 40mFrontier
Deal found 8/17$158

Cheapflights Fare Finder

 
Customize your flight search to find flights from Ontario to Missouri 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 August 20, 2025.
Use the filters below to find and compare flights from Ontario to Missouri that are best for you.

Fly from

Ontario

Fly to

Missouri

Route

Depart

Return

Price

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

Tue 9/2

12:59 am-9:11 am

1 stop6h 12m

Lambert-St Louis

Sun 9/7

7:55 pm-7:54 pm

1 stop25h 59m

$142

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

Fri 9/12

8:59 pm-9:06 am

1 stop10h 07m

Lambert-St Louis

Wed 9/17

7:55 pm-7:23 am

1 stop13h 28m

$143

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

Sun 10/12

6:53 am-9:07 am

1 stop24h 14m

Lambert-St Louis

Sat 10/18

7:52 pm-9:35 am

1 stop15h 43m

$143

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

Tue 9/2

12:59 am-9:11 am

1 stop6h 12m

Lambert-St Louis

Fri 9/5

7:55 pm-7:54 pm

1 stop25h 59m

$143

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

Sat 9/13

8:59 pm-9:06 am

1 stop10h 07m

Lambert-St Louis

Mon 9/15

7:55 pm-7:54 pm

1 stop25h 59m

$143

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

Thu 9/18

8:59 pm-9:06 am

1 stop10h 07m

Lambert-St Louis

Tue 9/23

7:55 pm-7:54 pm

1 stop25h 59m

$143

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

Tue 9/16

8:59 pm-9:06 am

1 stop10h 07m

Lambert-St Louis

Fri 9/19

7:55 pm-7:54 pm

1 stop25h 59m

$143

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

Sat 9/6

8:59 pm-9:06 am

1 stop10h 07m

Lambert-St Louis

Wed 9/10

7:55 pm-7:23 am

1 stop13h 28m

$143

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

Fri 9/26

8:59 pm-9:06 am

1 stop10h 07m

Lambert-St Louis

Sat 9/27

7:55 pm-7:23 am

1 stop13h 28m

$143

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

Tue 9/23

8:59 pm-9:06 am

1 stop10h 07m

Lambert-St Louis

Wed 9/24

7:55 pm-7:23 am

1 stop13h 28m

$143

Flights are sorted by cheapest round-trip flights first.

Deals found on 8/18

Showing 1-10 of 59 results
1
2
3
...
6

Best time to book a flight from Ontario to Missouri

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

Cheapflights Insights

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

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

Currently, August is the cheapest month in which you can book a flight from Ontario to Missouri (average of $311). Flying from Ontario to Missouri in March is currently the most expensive (average of $356). 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.

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

Find hourly flight availability from Ontario to Missouri. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated August 20, 2025.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Ontario to Missouri as you normally would.

Reviews of airlines servicing Missouri

Get insights into the airlines that provide service to Missouri. 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 Missouri. Reviews last updated August 20, 2025.
See what other customers who have flown with Southwest, Delta, and United Airlines from Ontario to Missouri have to say. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,246 reviews

Overall

8.0

Food

7.0

Boarding

8.1

Crew

8.6

Entertainment

7.5

Comfort

8.0

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
Southwest
8.0
Very good
4,246 reviews
Southwest
8.0
Very good
4,246 reviews

Overall

8.0

Food

7.0

Boarding

8.1

Crew

8.6

Entertainment

7.5

Comfort

8.0

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
Delta
8.0
Very good
7,982 reviews
Southwest
8.0
Very good
4,246 reviews

Overall

8.0

Food

7.0

Boarding

8.1

Crew

8.6

Entertainment

7.5

Comfort

8.0

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
United Airlines
7.4
Good
8,928 reviews
Southwest
8.0
Very good
4,246 reviews

Overall

8.0

Food

7.0

Boarding

8.1

Crew

8.6

Entertainment

7.5

Comfort

8.0

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
American Airlines
7.2
Good
10,000 reviews
Southwest
8.0
Very good
4,246 reviews

Overall

8.0

Food

7.0

Boarding

8.1

Crew

8.6

Entertainment

7.5

Comfort

8.0

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
Frontier
5.8
Fair
3,207 reviews
Southwest
8.0
Very good
4,246 reviews

Overall

8.0

Food

7.0

Boarding

8.1

Crew

8.6

Entertainment

7.5

Comfort

8.0

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.

Related info for your journey

Find useful and relevant information for your journey from Ontario to Missouri. 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 from for flights from Ontario to Missouri?

    Located just 3.1 mi from the city center, Ontario (ONT) is the airport most travelers will use when flying to Missouri from Ontario.

  • How long is the flight from Ontario to Missouri?

    Airlines like Frontier and Delta fly from Ontario to Missouri in about 6h 12m. The time it takes to get you to your destination can typically vary by up to 1h 55m. The distance between Ontario and Missouri is about 1541 mi. Both multi-stop and nonstop flights can be found to your destination and back.

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

    The most popular route from Ontario to Missouri is Ontario - Kansas City. You may also consider Ontario - Lambert-St Louis or Ontario - Springfield-Branson.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Ontario to Missouri 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 Ontario to Missouri?

    Currently, August is the cheapest month in which you can book a flight from Ontario to Missouri (average of $311). Flying from Ontario to Missouri in March is currently the most expensive (average of $356). 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

Browse thousands of different options on Cheapflights for your next trip

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

Alternative routes for Ontario to Missouri

See prices for flight routes from nearby airports that may be better suited for you.
Los Angeles to John F Kennedy Intl flights
Los Angeles to Newark flights
San Francisco to John F Kennedy Intl flights
Los Angeles to Seattle flights
Ontario to Seattle flights
San Francisco to Newark flights
Los Angeles to Dallas/Fort Worth flights
Los Angeles to LaGuardia flights
Los Angeles to O'Hare Intl flights
San Francisco to Las Vegas flights
Los Angeles to Honolulu flights
Los Angeles to San Francisco flights
San Francisco to Seattle flights
Los Angeles to Las Vegas flights
San Francisco to O'Hare Intl flights
Ontario to John F Kennedy Intl flights
San Francisco to Los Angeles flights
San Jose to Seattle flights
San Francisco to LaGuardia flights
Santa Ana to Las Vegas flights
Burbank to Las Vegas flights
San Francisco to Santa Ana flights
Los Angeles to San Jose flights
Los Angeles to Boston flights
San Francisco to Dallas/Fort Worth flights
Santa Ana to Seattle flights
San Jose to Los Angeles flights
Oakland to Las Vegas flights
Los Angeles to Portland flights
San Francisco to Honolulu flights
Santa Ana to San Francisco flights
Burbank to Newark flights
Los Angeles to Miami flights
San Jose to Las Vegas flights
Los Angeles to Dulles Intl flights
San Diego to Seattle flights
Los Angeles to Reagan-National flights
Santa Ana to Newark flights
Ontario to San Francisco flights
San Francisco to Denver flights
Ontario to Newark flights
San Francisco to Ontario flights
Los Angeles to Denver flights
Ontario to O'Hare Intl flights
Los Angeles to Orlando flights
San Diego to John F Kennedy Intl flights
San Francisco to Boston flights
Los Angeles to Fort Lauderdale flights
Los Angeles to Austin flights
San Francisco to Dulles Intl flights

Top 5 airlines flying from Ontario to Missouri

Discover the top 5 airlines that operate flights from Ontario to Missouri. 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 August 20, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$108Average$231FlexibilityNo cancel feeOn-time62%
DeltaCheapest$195Average$393FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$247Average$427FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$268Average$448FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$278Average$477FlexibilityNo cancel feeOn-time69%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.