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Missouri

$62+ 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 1/23. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — STL
Dec 13 — Dec 201
Sat 12/13
Sat 12/20
1 adult, Economy
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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 November 13, 2025.

This Kiwi.com deal was found by Cheapflights users on 11/12. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/276:30 amONT - STL
1 stop12h 39mFrontier
Mon 12/19:54 pmSTL - ONT
1 stop25h 23mFrontier
Deal found 11/12$131
This CheapOair deal was found by Cheapflights users on 11/12. 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.
Thu 12/1112:04 pmONT - STL
1 stop20h 10mFrontier
Sun 12/1410:44 pmSTL - ONT
1 stop24h 33mFrontier
Deal found 11/12$134
This CheapOair deal was found by Cheapflights users on 11/13. 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.
Thu 12/112:59 pmONT - STL
1 stop19h 13mFrontier
Thu 12/185:19 pmSTL - ONT
1 stop25h 50mFrontier
Deal found 11/13$137
This CheapOair deal was found by Cheapflights users on 11/12. 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.
Wed 12/36:15 amONT - STL
1 stop27h 57mFrontier
Wed 12/107:43 pmSTL - ONT
1 stop17h 26mFrontier
Deal found 11/12$138
This Booking.com deal was found by Cheapflights users on 11/11. 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 12/46:15 amONT - STL
1 stop27h 57mFrontier
Mon 12/81:16 pmSTL - ONT
1 stop10h 01mFrontier
Deal found 11/11$139
This CheapOair deal was found by Cheapflights users on 11/12. 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.
Fri 12/56:15 amONT - STL
1 stop13h 33mFrontier
Sun 12/79:14 pmSTL - ONT
1 stop26h 03mFrontier
Deal found 11/12$142
This CheapOair deal was found by Cheapflights users on 11/11. 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 11/2512:58 amONT - STL
1 stop7h 04mFrontier
Sun 11/309:54 pmSTL - ONT
1 stop25h 12mFrontier
Deal found 11/11$144
This Kiwi.com deal was found by Cheapflights users on 11/12. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/205:16 pmONT - MCI
2 stops24h 35mFrontier
Wed 12/248:45 pmMCI - ONT
1 stop29h 14mFrontier
Deal found 11/12$156
This Trip.com deal was found by Cheapflights users on 11/11. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/2612:58 amONT - STL
1 stop16h 00mFrontier
Sun 11/309:54 pmSTL - ONT
1 stop25h 12mFrontier
Deal found 11/11$172
This Kiwi.com deal was found by Cheapflights users on 11/12. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/206:00 amONT - MCI
1 stop6h 52mMultiple Airlines
Wed 12/248:45 pmMCI - ONT
1 stop29h 14mMultiple Airlines
Deal found 11/12$173
This Kiwi.com deal was found by Cheapflights users on 11/12. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/296:00 amONT - MCI
2 stops35h 50mFrontier
Mon 1/58:45 pmMCI - ONT
1 stop28h 29mFrontier
Deal found 11/12$174
This CheapOair deal was found by Cheapflights users on 11/10. 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.
Sat 12/66:15 amONT - STL
1 stop27h 57mFrontier
Mon 12/81:16 pmSTL - ONT
1 stop10h 01mFrontier
Deal found 11/10$176

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 November 13, 2025.

Most accurate provider

CheapOair
3 stars

Most trusted provider

CheapOair
3 stars

Round-trip from

$130
(Frontier)

One-way from

$62
(Trip.com)

Popular in

December

Cheapest in

October

Average price

$419
Provider with most accurate pricing for Los Angeles-Lambert-St Louis flight deals.
Search Deals
Provider most trusted by Cheapflights users for Los Angeles-Lambert-St Louis flights.
Search Deals
From Ontario to Missouri
Search Deals
One-way flight from Ontario to Missouri
Search Deals
Highest demand for flights based on searches. 5% potential increase in price ($21 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 November 2025
Search Deals

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 November 13, 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

Fri 12/12

6:15 am-9:48 pm

1 stop13h 33m

Lambert-St Louis

Mon 12/15

1:16 pm-9:17 pm

1 stop10h 01m

$134

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

Thu 1/8

8:14 pm-4:49 pm

1 stop18h 35m

Lambert-St Louis

Sun 1/11

5:44 pm-2:31 pm

1 stop22h 47m

$134

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

Thu 12/11

2:59 pm-12:12 pm

1 stop19h 13m

Lambert-St Louis

Thu 12/18

5:19 pm-5:09 pm

1 stop25h 50m

$137

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

Fri 12/19

6:00 am-9:25 pm

1 stop13h 25m

Lambert-St Louis

Sun 12/21

10:10 pm-5:15 pm

1 stop21h 05m

$144

OntarioKansas City

ONT - MCI

ONTMCI

Ontario

Mon 12/29

6:45 am-7:50 pm

1 stop11h 05m

Kansas City

Mon 1/5

8:45 pm-11:14 pm

1 stop28h 29m

$191

OntarioKansas City

ONT - MCI

ONTMCI

Ontario

Thu 12/4

6:15 am-2:52 pm

1 stop6h 37m

Kansas City

Sun 12/7

8:45 pm-2:25 pm

1 stop19h 40m

$194

OntarioKansas City

ONT - MCI

ONTMCI

Ontario

Mon 12/15

5:18 pm-8:44 pm

1 stop25h 26m

Kansas City

Thu 12/18

7:00 am-5:22 pm

1 stop12h 22m

$196

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

Fri 12/19

6:00 am-9:25 pm

1 stop13h 25m

Lambert-St Louis

Sat 12/20

10:10 pm-5:42 pm

1 stop21h 32m

$198

OntarioKansas City

ONT - MCI

ONTMCI

Ontario

Fri 12/19

5:54 pm-7:51 pm

2 stops23h 57m

Kansas City

Wed 12/24

8:45 pm-11:59 pm

1 stop29h 14m

$201

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

Sat 12/6

6:15 am-12:12 pm

1 stop27h 57m

Lambert-St Louis

Mon 12/8

12:07 pm-11:27 am

2 stops25h 20m

$203

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/12

Showing 1-10 of 60 results
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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, June is the cheapest month in which you can book a flight from Ontario to Missouri (average of $60). Flying from Ontario to Missouri in April is currently the most expensive (average of $143). 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 November 13, 2025.

It’s optimal to fly from Ontario to Missouri in the evening. By choosing this option you can save up to 54% on the cost of your flight, compared to a flight in the morning.

What is the cheapest day to fly from Ontario to Missouri?

Use this chart to determine the cheapest time to fly round-trip from Ontario to Missouri. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Ontario to Missouri flight should consider departing on Wednesday at noon when fares are most often at their lowest. Sunday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.

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 November 13, 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
4,242 reviews

Comfort

8.0

Crew

8.6

Food

7.0

Boarding

8.1

Entertainment

7.5

Overall

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
4,242 reviews
Southwest
8.0
Very good
4,242 reviews

Comfort

8.0

Crew

8.6

Food

7.0

Boarding

8.1

Entertainment

7.5

Overall

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
7.9
Good
8,007 reviews
Southwest
8.0
Very good
4,242 reviews

Comfort

8.0

Crew

8.6

Food

7.0

Boarding

8.1

Entertainment

7.5

Overall

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
9,017 reviews
Southwest
8.0
Very good
4,242 reviews

Comfort

8.0

Crew

8.6

Food

7.0

Boarding

8.1

Entertainment

7.5

Overall

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
11,051 reviews
Southwest
8.0
Very good
4,242 reviews

Comfort

8.0

Crew

8.6

Food

7.0

Boarding

8.1

Entertainment

7.5

Overall

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
3,109 reviews
Southwest
8.0
Very good
4,242 reviews

Comfort

8.0

Crew

8.6

Food

7.0

Boarding

8.1

Entertainment

7.5

Overall

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 8h 35m. The time it takes to get you to your destination can typically vary by up to 4h 58m. The distance between Ontario and Missouri is about 1372 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, June is the cheapest month in which you can book a flight from Ontario to Missouri (average of $60). Flying from Ontario to Missouri in April is currently the most expensive (average of $143). 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 Ontario to Missouri

See prices for flight routes from nearby airports that may be better suited for you.
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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 November 13, 2025.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$98Average$376FlexibilityNo cancel feeOn-timeN/A
FrontierCheapest$115Average$223FlexibilityNo cancel feeOn-time62%
SouthwestCheapest$247Average$420FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$256Average$464FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$268Average$450FlexibilityNo cancel feeOn-time71%

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