Cheap flights from St. Louis to Ontario (STL - ONT) from $46

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 5/1. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
STL — ONT
Apr 28 — May 51

The best prices from Lambert-St Louis to Ontario are usually found in August or September, booked 38 days in advance, depart on a Thursday or Monday and return on a Saturday

Cheap flight deals from St. Louis to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Ontario (ONT). 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 April 23, 2024.

Popular in

June

Cheapest in

August

Round-trip from

$238

One-way from

$181
High demand for flights, 34% potential price rise
Best time to find cheap flights, 46% potential price drop
From Lambert-St Louis to Ontario
One-way flight from Lambert-St Louis to Ontario

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

Thursday flights are generally found to be more expensive for flights from St. Louis to Ontario. This shouldn’t discourage you from searching, as you can still find great deals by being flexible with your options. Use our search form to find deals on tickets to Ontario.

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

Travelers have found it’s best to book a flight 58 days in advance to save up to 30% compared to booking the same week of travel. As your travel date approaches, the cost of this flight route may potentially increase. While opting to book 58 days out may not be an option for all, there are still additional ways to secure a deal in the near future. You might find a flight from St. Louis to Ontario 1-2 weeks in advance for as low as $477, or $754 for flights within the next 24 hours.

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

Our data shows that January tends to be the cheapest month to fly to Ontario from St. Louis. Users have commonly found prices around $446 for the month, but tickets can be as low as $177. Due to multiple factors, prepare for potentially higher prices in March.

When is the cheapest time to fly from St. Louis to Ontario (STL - ONT)?

It’s optimal to fly from St. Louis to Ontario in the evening. By choosing this option you can save up to 56% on the cost of your flight, compared to a flight at noon.

Cheap Frontier flights from St. Louis to Ontario

Explore cheap flight options specifically provided by Frontier for the route between St. Louis and Ontario. Find affordable fares and compare prices with other airlines to secure the best deal for your journey. Over the last 7 days, Cheapflights users made 3,086,534 searches. Data last updated April 23, 2024.
Consider these cheap Frontier flights we've found departing from St. Louis to Ontario. Make sure to double check the flight details before booking.
Sat 5/188:04 pmSTL - ONT
1 stop5h 55mFrontier
Mon 5/2012:59 amONT - STL
1 stop10h 10mFrontier
Deal found 4/21$76
Wed 5/158:04 pmSTL - ONT
1 stop5h 55mFrontier
Wed 5/2211:30 pmONT - STL
1 stop8h 43mFrontier
Deal found 4/22$88
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Tue 5/2112:59 amONT - STL
1 stop6h 37mFrontier
Deal found 4/22$89
Fri 5/176:40 pmSTL - ONT
1 stop21h 55mFrontier
Tue 5/212:25 pmONT - STL
1 stop17h 11mFrontier
Deal found 4/21$99
Fri 5/178:45 pmSTL - ONT
1 stop12h 49mFrontier
Mon 5/2012:59 amONT - STL
1 stop10h 10mFrontier
Deal found 4/21$100
Thu 5/165:01 pmSTL - ONT
1 stop27h 22mFrontier
Sun 5/196:09 pmONT - STL
1 stop14h 04mFrontier
Deal found 4/22$101
Sat 5/118:04 pmSTL - ONT
1 stop5h 55mFrontier
Tue 5/1410:49 pmONT - STL
1 stop9h 29mFrontier
Deal found 4/22$102
Sat 5/1112:39 pmSTL - ONT
1 stop6h 20mFrontier
Tue 5/1412:39 pmONT - STL
1 stop7h 20mFrontier
Deal found 4/22$103
Fri 5/107:51 pmSTL - ONT
1 stop28h 07mFrontier
Mon 5/1310:59 pmONT - STL
1 stop21h 00mFrontier
Deal found 4/22$104

Cheap United Airlines flights from St. Louis to Ontario

Explore cheap flight options specifically provided by United Airlines for the route between St. Louis and Ontario. Find affordable fares and compare prices with other airlines to secure the best deal for your journey. Over the last 7 days, Cheapflights users made 3,086,534 searches. Data last updated April 23, 2024.
Have a look at some of the cheapest available United Airlines flights departing from St. Louis and landing in Ontario. If these deals don't fit your criteria, make sure to check back soon as new deals are always added.
Sat 5/188:05 amSTL - ONT
2 stops16h 59mUnited Airlines
Tue 5/211:36 pmONT - STL
2 stops24h 10mUnited Airlines
Deal found 4/21$520
Fri 5/175:25 pmSTL - ONT
2 stops31h 39mUnited Airlines
Tue 5/211:36 pmONT - STL
2 stops18h 38mUnited Airlines
Deal found 4/21$536
Wed 5/81:37 pmSTL - ONT
2 stops11h 27mUnited Airlines
Sun 5/125:15 amONT - STL
1 stop9h 23mUnited Airlines
Deal found 4/22$591
Mon 5/135:25 pmSTL - ONT
2 stops21h 15mUnited Airlines
Thu 5/235:15 amONT - STL
1 stop9h 14mUnited Airlines
Deal found 4/22$609
Tue 4/3010:10 amSTL - ONT
2 stops12h 30mUnited Airlines
Wed 5/15:15 amONT - STL
1 stop9h 23mUnited Airlines
Deal found 4/21$631
Mon 5/135:25 pmSTL - ONT
3 stops18h 36mUnited Airlines
Thu 5/235:15 amONT - STL
1 stop9h 14mUnited Airlines
Deal found 4/22$704
Thu 5/26:00 amSTL - ONT
2 stops16h 53mUnited Airlines
Sun 5/51:36 pmONT - STL
2 stops22h 47mUnited Airlines
Deal found 4/22$705
Tue 4/3010:10 amSTL - ONT
2 stops12h 30mUnited Airlines
Wed 5/15:15 amONT - STL
2 stops8h 31mUnited Airlines
Deal found 4/21$784
Fri 9/204:51 pmSTL - ONT
1 stop6h 11mUnited Airlines
Fri 9/276:02 amONT - STL
1 stop8h 20mUnited Airlines
Deal found 4/21$904

Cheap St. Louis to Ontario flights in April & May 2024

Find cheap flight options from St. Louis to Ontario specifically for the months of April and May 2024. Explore affordable fares based on user searches. Over the last 7 days, Cheapflights users made 3,086,534 searches. Prices were last updated on April 23, 2024.
Scroll through some of the best deals on flights from St. Louis to Ontario in 2024. For more flight deals, be sure to check back very soon.
Sat 5/188:04 pmSTL - ONT
1 stop5h 55mFrontier
Mon 5/2012:59 amONT - STL
1 stop10h 10mFrontier
Deal found 4/21$76
Wed 5/158:04 pmSTL - ONT
1 stop5h 55mFrontier
Wed 5/2211:30 pmONT - STL
1 stop8h 43mFrontier
Deal found 4/22$88
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Tue 5/2112:59 amONT - STL
1 stop6h 37mFrontier
Deal found 4/22$89
Fri 5/176:40 pmSTL - ONT
1 stop21h 55mFrontier
Tue 5/212:25 pmONT - STL
1 stop17h 11mFrontier
Deal found 4/21$99
Fri 5/178:45 pmSTL - ONT
1 stop12h 49mFrontier
Tue 5/2112:59 amONT - STL
1 stop6h 37mFrontier
Deal found 4/23$100
Thu 5/165:01 pmSTL - ONT
1 stop27h 22mFrontier
Sun 5/196:09 pmONT - STL
1 stop14h 04mFrontier
Deal found 4/22$101
Sat 5/118:04 pmSTL - ONT
1 stop5h 55mFrontier
Tue 5/1410:49 pmONT - STL
1 stop9h 29mFrontier
Deal found 4/22$102
Sat 5/1112:39 pmSTL - ONT
1 stop6h 20mFrontier
Tue 5/1412:39 pmONT - STL
1 stop7h 20mFrontier
Deal found 4/22$103
Fri 5/107:51 pmSTL - ONT
1 stop28h 07mFrontier
Mon 5/1310:59 pmONT - STL
1 stop21h 00mFrontier
Deal found 4/22$104

St. Louis to Ontario 2024 flight deals

Discover exclusive flight deals for travel between St. Louis and Ontario in 2024. Find excellent offers based on user searches. Over the last 7 days, Cheapflights users made 3,086,534 searches. Data last updated April 23, 2024.
Scroll through some of the best deals on flights from St. Louis to Ontario in 2024. For more flight deals, be sure to check back very soon.
Sat 5/188:04 pmSTL - ONT
1 stop5h 55mFrontier
Mon 5/2012:59 amONT - STL
1 stop10h 10mFrontier
Deal found 4/21$76
Wed 5/158:04 pmSTL - ONT
1 stop5h 55mFrontier
Wed 5/2211:30 pmONT - STL
1 stop8h 43mFrontier
Deal found 4/22$88
Wed 5/154:39 pmSTL - ONT
1 stop7h 21mFrontier
Tue 5/2112:59 amONT - STL
1 stop6h 37mFrontier
Deal found 4/22$89
Fri 5/176:40 pmSTL - ONT
1 stop21h 55mFrontier
Tue 5/212:25 pmONT - STL
1 stop17h 11mFrontier
Deal found 4/21$99
Fri 5/178:45 pmSTL - ONT
1 stop12h 49mFrontier
Tue 5/2112:59 amONT - STL
1 stop6h 37mFrontier
Deal found 4/23$100
Thu 5/165:01 pmSTL - ONT
1 stop27h 22mFrontier
Sun 5/196:09 pmONT - STL
1 stop14h 04mFrontier
Deal found 4/22$101
Sat 5/118:04 pmSTL - ONT
1 stop5h 55mFrontier
Tue 5/1410:49 pmONT - STL
1 stop9h 29mFrontier
Deal found 4/22$102
Sat 5/1112:39 pmSTL - ONT
1 stop6h 20mFrontier
Tue 5/1412:39 pmONT - STL
1 stop7h 20mFrontier
Deal found 4/22$103
Fri 5/107:51 pmSTL - ONT
1 stop28h 07mFrontier
Mon 5/1310:59 pmONT - STL
1 stop21h 00mFrontier
Deal found 4/22$104

St. Louis to Ontario flights leaving soon

Find last-minute flight options from St. Louis to Ontario 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 3,086,534 searches. Data last updated April 23, 2024.
Have a look at some of the last-minute flights available departing from St. Louis to Ontario. It's wise to confirm all flight details are correct before booking.
Wed 5/18:04 pmSTL - ONT
1 stop5h 55mFrontier
Thu 5/210:58 pmONT - STL
1 stop9h 20mFrontier
Deal found 4/23$106
Tue 4/304:50 pmSTL - ONT
1 stop9h 09mFrontier
Wed 5/110:49 pmONT - STL
1 stop9h 29mFrontier
Deal found 4/21$120
Fri 5/35:35 pmSTL - ONT
1 stop8h 20mFrontier
Tue 5/712:59 amONT - STL
1 stop6h 48mFrontier
Deal found 4/22$140
Thu 5/210:59 pmSTL - ONT
1 stop10h 09mFrontier
Sat 5/412:59 amONT - STL
1 stop11h 30mFrontier
Deal found 4/22$141
Thu 5/211:38 amSTL - ONT
1 stop14h 18mFrontier
Sun 5/57:31 amONT - STL
1 stop24h 16mFrontier
Deal found 4/22$150
Fri 5/35:35 pmSTL - ONT
1 stop8h 20mFrontier
Sat 5/412:59 amONT - STL
1 stop11h 30mFrontier
Deal found 4/22$162
Wed 5/18:04 pmSTL - ONT
1 stop5h 55mFrontier
Thu 5/26:55 pmONT - STL
2 stops13h 23mFrontier
Deal found 4/23$171
Fri 5/37:51 pmSTL - ONT
1 stop18h 35mFrontier
Sun 5/57:31 amONT - STL
1 stop24h 16mFrontier
Deal found 4/22$172
Fri 5/35:35 pmSTL - ONT
1 stop8h 20mFrontier
Sun 5/512:59 amONT - STL
1 stop6h 48mFrontier
Deal found 4/22$210

One-way flights to Ontario from St. Louis

Search for one-way flight options from St. Louis to Ontario. 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 3,086,534 searches. Data last updated April 23, 2024.
Users in need of a one-way flight from St. Louis to Ontario can choose from these deals. Users in need of a round-trip flight from St. Louis to Ontario instead should update the search form at the top of page.
Wed 5/18:04 pmSTL - ONT
1 stop5h 55mFrontier
Deal found 4/21$46
Wed 5/2210:21 pmSTL - ONT
1 stop12h 19mFrontier
Deal found 4/21$51
Sat 6/18:04 pmSTL - ONT
1 stop5h 55mFrontier
Deal found 4/22$53
Mon 5/207:23 pmSTL - ONT
1 stop15h 41mFrontier
Deal found 4/22$55
Thu 5/237:23 pmSTL - ONT
1 stop16h 01mFrontier
Deal found 4/22$57
Fri 5/178:45 pmSTL - ONT
1 stop12h 49mFrontier
Deal found 4/22$61
Tue 5/710:59 pmSTL - ONT
1 stop10h 09mFrontier
Deal found 4/22$65
Sun 5/1210:59 pmSTL - ONT
1 stop10h 04mFrontier
Deal found 4/22$66
Thu 4/2510:59 pmSTL - ONT
1 stop10h 09mFrontier
Deal found 4/22$67

Find flights from St. Louis to Ontario within your budget

Customize your flight search to find flights from St. Louis 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 3,086,534 searches. Data last updated April 23, 2024.

Fly from

Any airport

Fly to

Any airport

Budget

$76 - $348

Route

Depart

Return

Price

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Sat 5/18

1 stop5h 55m

Ontario

Mon 5/20

1 stop10h 10m

$76

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Wed 5/15

1 stop5h 55m

Ontario

Wed 5/22

1 stop8h 43m

$88

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Wed 5/15

1 stop7h 21m

Ontario

Tue 5/21

1 stop6h 37m

$89

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Fri 5/17

1 stop21h 55m

Ontario

Tue 5/21

1 stop17h 11m

$99

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Fri 5/17

1 stop12h 49m

Ontario

Mon 5/20

1 stop10h 10m

$100

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Thu 5/16

1 stop27h 22m

Ontario

Sun 5/19

1 stop14h 04m

$101

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Sat 5/11

1 stop5h 55m

Ontario

Tue 5/14

1 stop9h 29m

$102

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Sat 5/11

1 stop6h 20m

Ontario

Tue 5/14

1 stop7h 20m

$103

Lambert-St LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Sat 5/18

1 stop5h 55m

Ontario

Tue 5/21

2 stops9h 31m

$348

Flights are sorted by cheapest first

Deals found on 4/21

When is the best time to book a flight from St. Louis to Ontario?

Use this chart to determine the optimal time to book a round-trip flight from St. Louis to Ontario. Price data was last updated on January 28, 2024.
The price you pay for your flight from St. Louis to Ontario may vary depending on when you book. For the best chance of a lower fare, look to book 37 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.
Search Deals

When is the cheapest time to fly from St. Louis to Ontario?

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

Average price of flights to Ontario by month

Plan your trip from St. Louis to Ontario by taking into account the cheapest months to travel. The average price of a one-way flight from St. Louis to Ontario is currently $58 while a round-trip flight costs $123. Price data was last updated on April 21, 2024.

Currently, October is the cheapest month in which you can book a flight from St. Louis to Ontario (average of $237). Flying from St. Louis to Ontario in June is currently the most expensive (average of $346). 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.

January

$270

February

$287

March

$281

April

$258

May

$271

June

$346

July

$335

August

$287

September

$258

October

$237

November

$268

December

$271

Temperature and rainfall in Ontario by month

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

LAX

Temperature

57.2 - 73.4 °F

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. 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 Ontario. Reviews last updated April 23, 2024.
Peruse reviews from past customers who have flown with Frontier, United Airlines and Delta from St. Louis to Ontario to help guide your decision. In addition to providing an overall rating, users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.2
Very good
6,193 reviews

Food

7.4

Boarding

8.3

Entertainment

7.8

Crew

8.7

Comfort

8.1

Overall

8.2

Reviews

1 / 10

The flight attendant on the flight was extremely unprofessional and obnoxious. He treated the entire plane as if we were on a seventh grade camping trip. He thought he was funny but was actually rude to us while we were on the ground waiting to continue to our final stop. It was like being stuck with a bad comedian for four solid hours. We flew from Chicago to Long Beach to Reno over 5 hours and they did not have any food other then graham crackers. Because of being delayed no one had time to get food in the airport between flights. Terrible experience and Southwest should look into this crew member.

Southwest
8.2
Very good
6,193 reviews
Southwest
8.2
Very good
6,193 reviews

Food

7.4

Boarding

8.3

Entertainment

7.8

Crew

8.7

Comfort

8.1

Overall

8.2

Reviews

1 / 10

The flight attendant on the flight was extremely unprofessional and obnoxious. He treated the entire plane as if we were on a seventh grade camping trip. He thought he was funny but was actually rude to us while we were on the ground waiting to continue to our final stop. It was like being stuck with a bad comedian for four solid hours. We flew from Chicago to Long Beach to Reno over 5 hours and they did not have any food other then graham crackers. Because of being delayed no one had time to get food in the airport between flights. Terrible experience and Southwest should look into this crew member.

8.1
Very good
9,102 reviews
Southwest
8.2
Very good
6,193 reviews

Food

7.4

Boarding

8.3

Entertainment

7.8

Crew

8.7

Comfort

8.1

Overall

8.2

Reviews

1 / 10

The flight attendant on the flight was extremely unprofessional and obnoxious. He treated the entire plane as if we were on a seventh grade camping trip. He thought he was funny but was actually rude to us while we were on the ground waiting to continue to our final stop. It was like being stuck with a bad comedian for four solid hours. We flew from Chicago to Long Beach to Reno over 5 hours and they did not have any food other then graham crackers. Because of being delayed no one had time to get food in the airport between flights. Terrible experience and Southwest should look into this crew member.

8.1
Very good
11,028 reviews
Southwest
8.2
Very good
6,193 reviews

Food

7.4

Boarding

8.3

Entertainment

7.8

Crew

8.7

Comfort

8.1

Overall

8.2

Reviews

1 / 10

The flight attendant on the flight was extremely unprofessional and obnoxious. He treated the entire plane as if we were on a seventh grade camping trip. He thought he was funny but was actually rude to us while we were on the ground waiting to continue to our final stop. It was like being stuck with a bad comedian for four solid hours. We flew from Chicago to Long Beach to Reno over 5 hours and they did not have any food other then graham crackers. Because of being delayed no one had time to get food in the airport between flights. Terrible experience and Southwest should look into this crew member.

7.4
Good
11,289 reviews
Southwest
8.2
Very good
6,193 reviews

Food

7.4

Boarding

8.3

Entertainment

7.8

Crew

8.7

Comfort

8.1

Overall

8.2

Reviews

1 / 10

The flight attendant on the flight was extremely unprofessional and obnoxious. He treated the entire plane as if we were on a seventh grade camping trip. He thought he was funny but was actually rude to us while we were on the ground waiting to continue to our final stop. It was like being stuck with a bad comedian for four solid hours. We flew from Chicago to Long Beach to Reno over 5 hours and they did not have any food other then graham crackers. Because of being delayed no one had time to get food in the airport between flights. Terrible experience and Southwest should look into this crew member.

7.3
Good
14,914 reviews
Southwest
8.2
Very good
6,193 reviews

Food

7.4

Boarding

8.3

Entertainment

7.8

Crew

8.7

Comfort

8.1

Overall

8.2

Reviews

1 / 10

The flight attendant on the flight was extremely unprofessional and obnoxious. He treated the entire plane as if we were on a seventh grade camping trip. He thought he was funny but was actually rude to us while we were on the ground waiting to continue to our final stop. It was like being stuck with a bad comedian for four solid hours. We flew from Chicago to Long Beach to Reno over 5 hours and they did not have any food other then graham crackers. Because of being delayed no one had time to get food in the airport between flights. Terrible experience and Southwest should look into this crew member.

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Ontario. 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 St. Louis to Ontario for under $100 on Cheapflights?

    Yes, there are multiple flights from St. Louis to Ontario for under $100. The cheapest flight booked recently is on Frontier for just $76, but on average you can expect to pay $113.

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

    There are currently 16+ open flights from St. Louis to Ontario within the next 7 days for less than $200.

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

    Frontier, at $76, was found to be the cheapest airline from St. Louis to Ontario.. Frontier is priced at 79% lower than the current average price of a flight leaving 3 months from now.

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

    The cheapest airline one-way is Frontier, with whom users have recently found tickets for as low as $46. However, be on the lookout for offers from American Airlines and Southwest, as they are both options that can get you from St. Louis to Ontario for a low price.

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

  • What does STL to ONT mean?

    Lambert-St Louis Airport is STL and Ontario Airport is ONT. These codes are created by the International Air Transport Association (IATA) and airlines use them to identify the departing and arrival airports in the flight routes they service.

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

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

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

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

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

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

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

    Yes. Cheapflights offers flight deals from St. Louis 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.

  • Can I find deals for flights from St. Louis to Ontario that allow pets onboard?

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

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

    The St. Louis to Ontario flight deals you see on this page were last updated on 4/23.

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for St. Louis to Ontario
See prices for flight routes from nearby airports that may be better suited for you.

Top 4 airlines flying from St. Louis to Ontario

Discover the top 4 airlines that operate flights from St. Louis 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 3,086,534 searches. Data last updated April 23, 2024.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$125Average$224FlexibilityNo cancel feeOn-time62%
Search Frontier flights
DeltaCheapest$286Average$426FlexibilityNo cancel feeOn-timeN/A
Search Delta flights
American AirlinesCheapest$309Average$504FlexibilityNo cancel feeOn-time71%
Search American Airlines flights
United AirlinesCheapest$337Average$621FlexibilityNo cancel feeOn-time69%
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Search flights from St. Louis to Ontario by cabin class

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

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When you search for this flight from St. Louis to Ontario, Cheapflights searches on 900+ travel sites to save you time finding great flight deals online. Additionally, we offer filter features so you can choose a preferred cabin class or airline, see different price ranges, and much more so you can book the flight for you.

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Certainly. Search results for flights to Ontario from St. Louis shown to you on Cheapflights can be narrowed down with different useful search filters, which includes flexible booking options.

Can Cheapflights notify me if prices for flights from St. Louis to Ontario become cheaper?

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