Find Cheap Flights from Lambert-St Louis to Ontario (STL - ONT)

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Mon 1/22
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Good to Know

Average Price:
$434
(avg. price over the last 2 weeks)
Good Deal:
$338
or less (round trip)

When to Book Flights from Lambert-St Louis to Ontario

Flight prices as travel date approaches
-1 day
-2 days

Top tips for Finding a Cheap Flight

Looking for a cheap flight? 25% of our users found flights on this route for $337 or less.
The cheapest flight from Lambert-St Louis to Ontario was found 49 days before departure, on average.
Book at least 1 week before departure in order to get a below-average price.
Morning departure is around 31% more expensive than an evening flight, on average*.
*Average of the lowest prices shown in KAYAK’s search results for departures within the next 30 days

FAQs for Booking Lambert-St Louis to Ontario Flights

How long does a flight from Lambert-St Louis to Ontario take?
An average nonstop flight takes 5h 20m, covering a distance of 1544 miles.
Which airlines provide the cheapest flights from Lambert-St Louis to Ontario?
In the past 3 days, the cheapest round-trip tickets were found on Frontier ($268) and Multiple Airlines ($334)
Do I need a passport to fly between Lambert-St Louis and Ontario?
No.
What’s the cheapest day of the week to fly Lambert-St Louis to Ontario?
For Lambert-St Louis to Ontario, Friday is the cheapest day to fly on average and Thursday is the most expensive. Flying from Ontario back to Lambert-St Louis, the best deals are generally found on Thursday, with Friday being the most expensive.

Book cheap flights from Lambert-St Louis to Ontario (round-trip)

Airports
Origin
St. Louis
$268
only
$268
Destination
Ontario
$268
only
$268
Fri, Feb 23
STL
ONT
21h 40m
Mon, Feb 26
ONT
STL
23h 00m
Trip: 4 days
5.7OkayShow reviews
Overall 5.7 Okay
Based on 33594 reviews
Overall
5.9
Boarding
6.4
Comfort
5.4
Crew
6.8
Entertainment
4.5
Food
4.7
ATL
LAS
Good 6.0

The crew was very friendly.

The seats were close together and not very comfortable. No entertainment, for example a movie for a 4 hour flight. You have to pay for everything. Only thing complimentary is water.

DCA
DEN
Okay 4.0

The crew was really nice.

So many delays. My flight was eventually cancelled on Friday and was rescheduled for Saturday. The Saturday flight was delayed. All in all, i wasted a vacation day on Friday, I paid for a hotel in Denver for Friday night that I was not able to get refunded, I missed out on a day in Denver. It was a huge bummer.

RDU
MCO
Mediocre 3.3

The dirt cheap, I can't believe an airline can operate at this low an airfare and still turn a profit-ticket prices

The hidden checked-baggage fees that were almost half the cost of the actual ticket for one bag. The non reclining seats. The lack of legroom. The feeling of cattle being herded into a slaughterhouse. The lack of friendliness with the RDU and MCO gate/ticket counter agents. The cost of having to pay $12 to ensure I sit beside my 5 year old son on the flight. Besides a free seat belt, having to pay for everything else under the sun. Surprised AC was free. Not even an in-flight magazine or barf bag. Which is exactly what I feel like doing after giving you my money......

IAD
MCO
Mediocre 2.0

Unorganized, confusing boarding, confusion with seating, unbelievable lines while checking bags. Literally the only redeeming factor was the price.

MIA
LGA
Mediocre 2.0

if you have a hard engagement that you have to make, i hate to say it, but use a bigger airline. These guys are not dependable nyc -> miami. Have had 2 flights cancelled and delayed over 6 hours in the last 6 months. Only one scheduled flight everyday. If you can risk it, fine, but otherwise not worth it.

Sun, May 13
STL
ONT
5h 20m
Wed, May 16
ONT
STL
11h 30m
Trip: 4 days
Overall 0.0 Poor
Based on 0 reviews
Wed, Apr 25
STL
ONT
11h 02m
Sat, Apr 28
ONT
STL
11h 18m
Trip: 4 days
5.7OkayShow reviews
Overall 5.7 Okay
Based on 33594 reviews
Overall
5.9
Boarding
6.4
Comfort
5.4
Crew
6.8
Entertainment
4.5
Food
4.7
MCI
TPA
Excellent 8.3

Crew was ameable and helpful.

A passenger that was intoxicated and incredibly loud. It was ok though, she was on her way to a cruise.

SLC
ATL
Excellent 10.0

I had my own row the whole trip.

SJC
LAS
Mediocre 2.0

couldn't change my reservation even though I made it less than 24 hours

The service

RDU
MCO
Mediocre 3.3

The dirt cheap, I can't believe an airline can operate at this low an airfare and still turn a profit-ticket prices

The hidden checked-baggage fees that were almost half the cost of the actual ticket for one bag. The non reclining seats. The lack of legroom. The feeling of cattle being herded into a slaughterhouse. The lack of friendliness with the RDU and MCO gate/ticket counter agents. The cost of having to pay $12 to ensure I sit beside my 5 year old son on the flight. Besides a free seat belt, having to pay for everything else under the sun. Surprised AC was free. Not even an in-flight magazine or barf bag. Which is exactly what I feel like doing after giving you my money......

ATL
LAS
Good 6.0

The crew was very friendly.

The seats were close together and not very comfortable. No entertainment, for example a movie for a 4 hour flight. You have to pay for everything. Only thing complimentary is water.

Wed, Apr 25
STL
ONT
11h 02m
Sat, Apr 28
ONT
STL
11h 18m
Trip: 4 days
5.7OkayShow reviews
Overall 5.7 Okay
Based on 33594 reviews
Overall
5.9
Boarding
6.4
Comfort
5.4
Crew
6.8
Entertainment
4.5
Food
4.7
DCA
DEN
Okay 4.0

The crew was really nice.

So many delays. My flight was eventually cancelled on Friday and was rescheduled for Saturday. The Saturday flight was delayed. All in all, i wasted a vacation day on Friday, I paid for a hotel in Denver for Friday night that I was not able to get refunded, I missed out on a day in Denver. It was a huge bummer.

ONT
AUS
Excellent 9.5

The crew were kind and efficient and the planes were clean and well maintained.

No entertainment on the flights, but that is to be expected for the price.

IAD
MCO
Mediocre 2.0

Unorganized, confusing boarding, confusion with seating, unbelievable lines while checking bags. Literally the only redeeming factor was the price.

RDU
MCO
Mediocre 3.3

The dirt cheap, I can't believe an airline can operate at this low an airfare and still turn a profit-ticket prices

The hidden checked-baggage fees that were almost half the cost of the actual ticket for one bag. The non reclining seats. The lack of legroom. The feeling of cattle being herded into a slaughterhouse. The lack of friendliness with the RDU and MCO gate/ticket counter agents. The cost of having to pay $12 to ensure I sit beside my 5 year old son on the flight. Besides a free seat belt, having to pay for everything else under the sun. Surprised AC was free. Not even an in-flight magazine or barf bag. Which is exactly what I feel like doing after giving you my money......

SLC
ATL
Excellent 10.0

I had my own row the whole trip.

Tue, Mar 6
STL
ONT
16h 33m
Tue, Mar 13
ONT
STL
15h 28m
Trip: 7 days
5.7OkayShow reviews
Overall 5.7 Okay
Based on 33594 reviews
Overall
5.9
Boarding
6.4
Comfort
5.4
Crew
6.8
Entertainment
4.5
Food
4.7
RDU
MCO
Mediocre 3.3

The dirt cheap, I can't believe an airline can operate at this low an airfare and still turn a profit-ticket prices

The hidden checked-baggage fees that were almost half the cost of the actual ticket for one bag. The non reclining seats. The lack of legroom. The feeling of cattle being herded into a slaughterhouse. The lack of friendliness with the RDU and MCO gate/ticket counter agents. The cost of having to pay $12 to ensure I sit beside my 5 year old son on the flight. Besides a free seat belt, having to pay for everything else under the sun. Surprised AC was free. Not even an in-flight magazine or barf bag. Which is exactly what I feel like doing after giving you my money......

SFO
ATL
Mediocre 2.0

Nothing

Everything was horrible!

MCI
TPA
Excellent 8.3

Crew was ameable and helpful.

A passenger that was intoxicated and incredibly loud. It was ok though, she was on her way to a cruise.

ATL
LAS
Good 6.0

The crew was very friendly.

The seats were close together and not very comfortable. No entertainment, for example a movie for a 4 hour flight. You have to pay for everything. Only thing complimentary is water.

DCA
DEN
Okay 4.0

The crew was really nice.

So many delays. My flight was eventually cancelled on Friday and was rescheduled for Saturday. The Saturday flight was delayed. All in all, i wasted a vacation day on Friday, I paid for a hotel in Denver for Friday night that I was not able to get refunded, I missed out on a day in Denver. It was a huge bummer.

Sat, May 12
STL
ONT
10h 50m
Fri, May 18
ONT
STL
11h 30m
Trip: 7 days
5.7OkayShow reviews
Overall 5.7 Okay
Based on 33594 reviews
Overall
5.9
Boarding
6.4
Comfort
5.4
Crew
6.8
Entertainment
4.5
Food
4.7
SFO
ATL
Mediocre 2.0

Nothing

Everything was horrible!

SLC
ATL
Excellent 10.0

I had my own row the whole trip.

DCA
DEN
Okay 4.0

The crew was really nice.

So many delays. My flight was eventually cancelled on Friday and was rescheduled for Saturday. The Saturday flight was delayed. All in all, i wasted a vacation day on Friday, I paid for a hotel in Denver for Friday night that I was not able to get refunded, I missed out on a day in Denver. It was a huge bummer.

CLE
MCO
Mediocre 2.3

enough space to move around

I dislike that once I got to the airport in Cleveland before boarding schools go to Orlando they charge me $45 for a suitcase that if I would have painted with my ticket it would have been $25 and that's what it told me I had to pay at the airport if I wasn't going to pay it with my ticket it was only $25 not $45 so they charge me $45 and then when I went to board the plane to go in they tried to charge me $45 for a backpack that fits under the seat and wasn't a carry on then they charge like $3 for a can of soda I don't think I'll ever recommend Frontier to anyone or I would never travel again with them that is ridiculous being a disabled person and being taken advantage of is unacceptable

ATL
LAS
Good 6.0

The crew was very friendly.

The seats were close together and not very comfortable. No entertainment, for example a movie for a 4 hour flight. You have to pay for everything. Only thing complimentary is water.

Fri, Jun 1
STL
ONT
10h 50m
Sun, Jun 10
ONT
STL
20h 51m
Trip: 10 days
5.7OkayShow reviews
Overall 5.7 Okay
Based on 33594 reviews
Overall
5.9
Boarding
6.4
Comfort
5.4
Crew
6.8
Entertainment
4.5
Food
4.7
ONT
AUS
Excellent 9.5

The crew were kind and efficient and the planes were clean and well maintained.

No entertainment on the flights, but that is to be expected for the price.

IAD
MCO
Mediocre 2.0

Unorganized, confusing boarding, confusion with seating, unbelievable lines while checking bags. Literally the only redeeming factor was the price.

DCA
DEN
Okay 4.0

The crew was really nice.

So many delays. My flight was eventually cancelled on Friday and was rescheduled for Saturday. The Saturday flight was delayed. All in all, i wasted a vacation day on Friday, I paid for a hotel in Denver for Friday night that I was not able to get refunded, I missed out on a day in Denver. It was a huge bummer.

MCI
TPA
Excellent 8.3

Crew was ameable and helpful.

A passenger that was intoxicated and incredibly loud. It was ok though, she was on her way to a cruise.

ATL
LAS
Good 6.0

The crew was very friendly.

The seats were close together and not very comfortable. No entertainment, for example a movie for a 4 hour flight. You have to pay for everything. Only thing complimentary is water.

Mon, Jul 16
STL
ONT
10h 21m
Mon, Jul 23
ONT
STL
11h 59m
Trip: 8 days
5.7OkayShow reviews
Overall 5.7 Okay
Based on 33594 reviews
Overall
5.9
Boarding
6.4
Comfort
5.4
Crew
6.8
Entertainment
4.5
Food
4.7
IAD
MCO
Mediocre 2.0

Unorganized, confusing boarding, confusion with seating, unbelievable lines while checking bags. Literally the only redeeming factor was the price.

SFO
ATL
Mediocre 2.0

Nothing

Everything was horrible!

DCA
DEN
Okay 4.0

The crew was really nice.

So many delays. My flight was eventually cancelled on Friday and was rescheduled for Saturday. The Saturday flight was delayed. All in all, i wasted a vacation day on Friday, I paid for a hotel in Denver for Friday night that I was not able to get refunded, I missed out on a day in Denver. It was a huge bummer.

SJC
LAS
Mediocre 2.0

couldn't change my reservation even though I made it less than 24 hours

The service

ONT
AUS
Excellent 9.5

The crew were kind and efficient and the planes were clean and well maintained.

No entertainment on the flights, but that is to be expected for the price.

Thu, Jan 25
STL
ONT
16h 42m
Sun, Jan 28
ONT
STL
17h 37m
Trip: 4 days
5.7OkayShow reviews
Overall 5.7 Okay
Based on 33594 reviews
Overall
5.9
Boarding
6.4
Comfort
5.4
Crew
6.8
Entertainment
4.5
Food
4.7
ATL
LAS
Good 6.0

The crew was very friendly.

The seats were close together and not very comfortable. No entertainment, for example a movie for a 4 hour flight. You have to pay for everything. Only thing complimentary is water.

SLC
ATL
Excellent 10.0

I had my own row the whole trip.

MCI
TPA
Excellent 8.3

Crew was ameable and helpful.

A passenger that was intoxicated and incredibly loud. It was ok though, she was on her way to a cruise.

SJC
LAS
Mediocre 2.0

couldn't change my reservation even though I made it less than 24 hours

The service

MIA
LGA
Mediocre 2.0

if you have a hard engagement that you have to make, i hate to say it, but use a bigger airline. These guys are not dependable nyc -> miami. Have had 2 flights cancelled and delayed over 6 hours in the last 6 months. Only one scheduled flight everyday. If you can risk it, fine, but otherwise not worth it.

Fri, Mar 30
STL
ONT
21h 35m
Sun, Apr 1
ONT
STL
15h 28m
Trip: 3 days
5.7OkayShow reviews
Overall 5.7 Okay
Based on 33594 reviews
Overall
5.9
Boarding
6.4
Comfort
5.4
Crew
6.8
Entertainment
4.5
Food
4.7
RDU
MCO
Mediocre 3.3

The dirt cheap, I can't believe an airline can operate at this low an airfare and still turn a profit-ticket prices

The hidden checked-baggage fees that were almost half the cost of the actual ticket for one bag. The non reclining seats. The lack of legroom. The feeling of cattle being herded into a slaughterhouse. The lack of friendliness with the RDU and MCO gate/ticket counter agents. The cost of having to pay $12 to ensure I sit beside my 5 year old son on the flight. Besides a free seat belt, having to pay for everything else under the sun. Surprised AC was free. Not even an in-flight magazine or barf bag. Which is exactly what I feel like doing after giving you my money......

SJC
LAS
Mediocre 2.0

couldn't change my reservation even though I made it less than 24 hours

The service

CLE
MCO
Mediocre 2.3

enough space to move around

I dislike that once I got to the airport in Cleveland before boarding schools go to Orlando they charge me $45 for a suitcase that if I would have painted with my ticket it would have been $25 and that's what it told me I had to pay at the airport if I wasn't going to pay it with my ticket it was only $25 not $45 so they charge me $45 and then when I went to board the plane to go in they tried to charge me $45 for a backpack that fits under the seat and wasn't a carry on then they charge like $3 for a can of soda I don't think I'll ever recommend Frontier to anyone or I would never travel again with them that is ridiculous being a disabled person and being taken advantage of is unacceptable

IAD
MCO
Mediocre 2.0

Unorganized, confusing boarding, confusion with seating, unbelievable lines while checking bags. Literally the only redeeming factor was the price.

DEN
SNA
Good 6.6

Basic service but smooth.

No food or drinks.

Show more results

Lambert-St Louis to Ontario Flight Information

Flights Arrive in Ontario
Flights Depart from Lambert-St Louis
Flight Price $268
Distance 1544 miles
Airlines Frontier
*
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The fares displayed include all taxes and fees for economy class travel and were found by the provider in the last 72 hours. Seats are limited and may not be available on all flights and days. Fares are subject to change and may not be available on all flights or dates of travel. Some carriers charge additional fees for extra checked bags. Please check the carriers' sites.