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$57+ 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 2/11. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — STL
nov. 21 — nov. 281
vie. 11/21
vie. 11/28
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 octubre 22, 2025.

This Kiwi.com deal was found by Cheapflights users on 10/22. 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.
mié. 11/128:45 amONT - MCI
1 stop6h 34mFrontier
lun. 11/178:28 pmMCI - ONT
1 stop26h 59mFrontier
Deal found 10/22$141
This Kiwi.com deal was found by Cheapflights users on 10/21. 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.
vie. 12/53:20 pmONT - STL
1 stop16h 54mFrontier
vie. 12/127:43 pmSTL - ONT
1 stop20h 42mFrontier
Deal found 10/21$153
This Frontier deal was found by Cheapflights users on 10/20. 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.
vie. 10/316:53 amONT - MCI
1 stop10h 40mFrontier
sáb. 11/18:28 pmMCI - ONT
1 stop5h 22mFrontier
Deal found 10/20$154
This Kiwi.com deal was found by Cheapflights users on 10/20. 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.
mar. 11/48:45 amONT - STL
1 stop22h 22mFrontier
sáb. 11/87:45 pmSTL - ONT
1 stop17h 25mFrontier
Deal found 10/20$155
This Booking.com deal was found by Cheapflights users on 10/20. 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.
vie. 11/74:05 pmONT - MCI
1 stop25h 28mFrontier
lun. 11/108:28 pmMCI - ONT
1 stop27h 01mFrontier
Deal found 10/20$156
This Kiwi.com deal was found by Cheapflights users on 10/21. 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.
mié. 11/58:45 amONT - MCI
1 stop6h 34mFrontier
lun. 11/108:28 pmMCI - ONT
1 stop27h 01mFrontier
Deal found 10/21$158
This Kiwi.com deal was found by Cheapflights users on 10/21. 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.
mar. 11/118:45 amONT - MCI
1 stop6h 34mFrontier
sáb. 11/158:28 pmMCI - ONT
1 stop16h 42mFrontier
Deal found 10/21$162
This Kiwi.com deal was found by Cheapflights users on 10/21. 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.
mié. 11/128:45 amONT - MCI
1 stop6h 34mFrontier
sáb. 11/158:28 pmMCI - ONT
1 stop16h 42mFrontier
Deal found 10/21$163
This Kiwi.com deal was found by Cheapflights users on 10/20. 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.
mar. 11/48:00 amONT - MCI
2 stops31h 19mFrontier
sáb. 11/88:28 pmMCI - ONT
1 stop16h 42mFrontier
Deal found 10/20$167
This Frontier deal was found by Cheapflights users on 10/21. 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.
jue. 11/66:00 amONT - STL
1 stop5h 57mFrontier
lun. 11/102:42 pmSTL - ONT
1 stop9h 15mFrontier
Deal found 10/21$170
This Booking.com deal was found by Cheapflights users on 10/21. 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.
jue. 12/412:04 pmONT - STL
1 stop20h 10mFrontier
mié. 12/107:43 pmSTL - ONT
1 stop17h 26mFrontier
Deal found 10/21$171
This Booking.com deal was found by Cheapflights users on 10/19. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 11/34:05 pmONT - STL
1 stop15h 02mFrontier
lun. 11/102:42 pmSTL - ONT
1 stop9h 15mFrontier
Deal found 10/19$172

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 octubre 22, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$153
(Kiwi.com)

One-way from

$57
(Trip.com)

Popular in

December

Cheapest in

April

Average price

$365
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. 4% potential increase in price ($19 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 October 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 octubre 22, 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

jue. 12/4

12:04 pm-10:14 am

1 stop20h 10m

Lambert-St Louis

mié. 12/10

7:43 pm-11:09 am

1 stop17h 26m

$171

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

mié. 11/12

8:45 am-9:07 am

1 stop22h 22m

Lambert-St Louis

jue. 11/13

7:45 pm-11:50 pm

1 stop6h 05m

$172

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

mié. 11/5

8:00 am-1:57 pm

1 stop27h 57m

Lambert-St Louis

sáb. 11/8

4:51 pm-8:42 pm

1 stop5h 51m

$172

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

jue. 11/13

10:05 am-11:24 am

2 stops23h 19m

Lambert-St Louis

lun. 11/17

7:45 pm-9:27 pm

1 stop27h 42m

$190

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

vie. 12/5

3:20 pm-10:14 am

1 stop16h 54m

Lambert-St Louis

dom. 12/7

10:42 am-2:25 pm

2 stops29h 43m

$207

OntarioKansas City

ONT - MCI

ONTMCI

Ontario

mié. 11/5

8:45 am-5:19 pm

1 stop6h 34m

Kansas City

lun. 11/10

8:28 pm-11:50 pm

1 stop5h 22m

$211

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

mié. 11/12

8:45 am-9:07 am

1 stop22h 22m

Lambert-St Louis

dom. 11/16

6:21 pm-6:49 pm

2 stops26h 28m

$221

OntarioSt. Louis

ONT - STL

ONTSTL

Ontario

jue. 12/4

2:59 pm-12:12 pm

1 stop19h 13m

Lambert-St Louis

dom. 12/7

10:44 pm-9:17 pm

1 stop24h 33m

$246

OntarioKansas City

ONT - MCI

ONTMCI

Ontario

dom. 11/16

10:43 pm-12:24 am

1 stop23h 41m

Kansas City

dom. 11/23

12:58 pm-2:26 pm

1 stop27h 28m

$250

OntarioKansas City

ONT - MCI

ONTMCI

Ontario

mar. 11/18

8:45 am-5:19 pm

1 stop6h 34m

Kansas City

vie. 11/28

8:28 pm-11:57 pm

1 stop5h 29m

$258

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/19

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 $145). 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 octubre 22, 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 octubre 22, 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
4,237 reviews

Crew

8.6

Food

7.0

Overall

8.0

Entertainment

7.5

Comfort

8.0

Boarding

8.1

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
4,237 reviews
Southwest
8.0
Very good
4,237 reviews

Crew

8.6

Food

7.0

Overall

8.0

Entertainment

7.5

Comfort

8.0

Boarding

8.1

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
7,981 reviews
Southwest
8.0
Very good
4,237 reviews

Crew

8.6

Food

7.0

Overall

8.0

Entertainment

7.5

Comfort

8.0

Boarding

8.1

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
8,990 reviews
Southwest
8.0
Very good
4,237 reviews

Crew

8.6

Food

7.0

Overall

8.0

Entertainment

7.5

Comfort

8.0

Boarding

8.1

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
11,028 reviews
Southwest
8.0
Very good
4,237 reviews

Crew

8.6

Food

7.0

Overall

8.0

Entertainment

7.5

Comfort

8.0

Boarding

8.1

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
3,129 reviews
Southwest
8.0
Very good
4,237 reviews

Crew

8.6

Food

7.0

Overall

8.0

Entertainment

7.5

Comfort

8.0

Boarding

8.1

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, Delta, and United Airlines fly from Ontario to Missouri in about 5h 20m. The time it takes to get you to your destination can typically vary by up to 22h 37m. The distance between Ontario and Missouri is about 1314 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines to fly from Ontario to Missouri one-way?

    For one-way options, check prices for Alaska Airlines. According to our data, you can fly for as low as $136. Users have also found prices from $140 and $147 on Delta and United Airlines, respectively.

  • 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 $145). 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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Alternative routes for Ontario to Missouri

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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 octubre 22, 2025.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$98Average$393FlexibilityNo cancel feeOn-timeN/A
FrontierCheapest$115Average$225FlexibilityNo cancel feeOn-time62%
SouthwestCheapest$247Average$424FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$256Average$464FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$268Average$449FlexibilityNo cancel feeOn-time71%

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