$250 Find Cheap Flights from Ontario to Costa Rica

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Ontario to Costa Rica departing on 8/25. 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.
1 adult
1 adult, Economy, 0 bags

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Cheap Flights from Ontario to Costa Rica

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
San José
San José1 stop$509
Liberia
Liberia2 stops$607
San José
San José1 stop$509
Liberia
Liberia2 stops$607

Book Cheap Ontario to Costa Rica Plane Tickets

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Ontario to Costa Rica that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Ontario to Costa Rica

Thu, Oct 1 - Tue, Oct 20
Avianca Logo
11:35 pm - 8:45 am
ONT
-
SJO
8h 10m
1 stop
Avianca Logo
3:10 pm - 9:45 pm
SJO
-
ONT
7h 35m
1 stop
$509Avianca
Tue, Sep 1 - Wed, Sep 9
Southwest Logo
5:45 am - 6:40 pm
ONT
-
SJO
11h 55m
2 stops
Southwest Logo
1:40 pm - 10:05 pm
SJO
-
ONT
9h 25m
1 stop
$514Southwest
Sat, Jun 13 - Sat, Jun 20
Avianca Logo
11:35 pm - 8:45 am
ONT
-
SJO
8h 10m
1 stop
Avianca Logo
3:10 pm - 9:45 pm
SJO
-
ONT
7h 35m
1 stop
$519Avianca
Fri, Sep 18 - Fri, Sep 25
Southwest Logo
6:00 am - 6:40 pm
ONT
-
SJO
11h 40m
2 stops
Southwest Logo
9:00 am - 9:45 pm
SJO
-
ONT
13h 45m
2 stops
$547Southwest
Thu, Aug 20 - Mon, Aug 24
American Airlines Logo
4:07 pm - 1:52 pm
ONT
-
SJO
20h 45m
2 stops
American Airlines Logo
1:29 pm - 11:43 am
SJO
-
ONT
23h 14m
2 stops
$549American Airlines
Wed, Aug 19 - Sun, Aug 23
American Airlines Logo
11:59 pm - 7:53 pm
ONT
-
SJO
18h 54m
2 stops
American Airlines Logo
2:56 pm - 9:34 am
SJO
-
ONT
19h 38m
2 stops
$554American Airlines
Fri, Sep 18 - Fri, Sep 25
United Airlines Logo
6:00 am - 7:37 pm
ONT
-
SJO
12h 37m
1 stop
United Airlines Logo
8:45 am - 8:16 pm
SJO
-
ONT
12h 31m
1 stop
$564United Airlines
Fri, Sep 18 - Fri, Sep 25
United Airlines Logo
7:13 pm - 7:15 am
ONT
-
SJO
11h 02m
1 stop
United Airlines Logo
7:55 am - 10:59 pm
SJO
-
ONT
16h 04m
2 stops
$569United Airlines
Tue, Jun 30 - Tue, Jul 28
JetBlue Logo
11:58 pm - 12:40 pm
ONT
-
LIR
11h 42m
1 stop
JetBlue Logo
2:00 pm - 10:35 pm
LIR
-
ONT
33h 35m
1 stop
$697JetBlue
Tue, Jun 30 - Wed, Jul 29
JetBlue Logo
11:58 pm - 12:40 pm
ONT
-
LIR
11h 42m
1 stop
JetBlue Logo
2:00 pm - 10:44 pm
LIR
-
ONT
33h 44m
1 stop
$699JetBlue
Booking Insights

KAYAK's insights & trends for Ontario to Costa Rica flights

Get data-powered insights and trends into flights from Ontario to Costa Rica to help you find the cheapest flights, the best time to fly and much more.

What is the cheapest month to fly from Ontario to Costa Rica?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Ontario to Costa Rica, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Ontario to Costa Rica is February, when tickets cost $119 (return) on average. On the other hand, the most expensive months are July and March, when the average cost of round-trip tickets is $436 and $393 respectively.

Good to know

Low seasonFebruary
Cheapest flight$250
Best time to beat the crowds but there is an average 3% increase in price.
Most popular time to fly with an average 20% increase in price.
Flight from Ontario to San José

FAQs - booking Costa Rica flights

  • How does KAYAK find such low prices on flights from Ontario to Costa Rica?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Ontario to Costa Rica.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Ontario to Costa Rica?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from Ontario to Costa Rica is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Ontario to Costa Rica?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly from Ontario to Costa Rica with an airline and back with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Ontario to Costa Rica?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying from Ontario to Costa Rica up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top 3 airlines serving from Ontario to Costa Rica

 
Need help choosing which airline to fly with from Ontario to Costa Rica? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.4
United AirlinesOverall score based on 9757 reviews
7.1Entertainment
7.3Comfort
6.6Food
7.7Boarding
8.1Crew
Airline reviews

Seat pitch is horrible especially on the 15 hour flight. Gate crew at SFO was Outstanding. The flight crew was also great.

6.0 GoodRoger, May 2026
ONT - SFO
Read more United Airlines reviews

Seat pitch is horrible especially on the 15 hour flight. Gate crew at SFO was Outstanding. The flight crew was also great.

Easy of boarding, helpfully staff at check in, surprisingly comfortable seating

Lost of requested seat assignments. Lost my husband's meal choice

My service dog and I were asked to deplane just before they closed the door - clearly very last minute they couldn’t find the documentation that I have filled out many many times before that is for flying service animals. I purposely purchase 3seats (a whole row) since he is large and not all passengers want to sit next to a dog on a cross country flight. The plane departed with my husband on it!!! They made me fill out a hard copy of the same form and had to reschedule me on a later flight where they could find 3 seats together!! I’ve done this so many times before - clearly the error was on their part in a technology glitch - but really people - do better!! Very traumatic - and my husband had to wait for us when he landed ….so bad. Poor pup was confused and tired.

Late plane. Only one crew on the ground so we b had to wait for Denver flight to come in, board, and depart. At 78 yrs of age I was not pleased trying to get my connection. What really made me angry was the notification you sent me to hurry up or I would miss my connection. Why tell me to hurry up when you got me in late. It was not a good way of treating customers.

My flight time was changed without any notification to me which ruined my time sensitive plans so I ended up completely changing my travel plans and no reimbursement.

No screens or meal options. Freezing cold. Dirty seats. Left late.

I liked that my son and I were reseated next to each other (we had different bookings). I liked that it was a directg flight and mostly on time. I liked that you provided pillows and blankets. Flight attendants were generally courteous. The messaging through wifi did not work well. The food was not good. Seats are very narrow and I felt slightly claustraphobic in the window seat.

Some crew were unfriendly or in some cases just straight up rude.

Booked through Kayak Business, had a seat in middle and towards back due to booking rate, not comfortable.

Ontario airport boarding was very easy to park and access, is clean and TSA took 10 minutes total. Check-in was a breeze and cruise was very nice.

It's a long flight and that is always difficult. I was comfortable and well. The movies available were great and the crew was good.

Premium Economy Good crew, good service, excellent food. Seat back screen just not bright enough.

The crew was very attentive through out the flight. Seats were comfortable, nice flight bag with pillow and blanket. Food was okay, since it was a overnight flight seemed to go by fast.

Left early arrived early..right amount of talking from pilots..of course had to love the biscuit and water!

Boarding gate at LAX was too crowded—two gates next to one another

On time departure and early arrival. Flight attendant very nice.

The business class layout of chairs was weired. You are sitting directly across stranger.,

The SFO Lounge crew were amazing. The bartender Faris was great. Thanks!

Friendly crew is the only nice thing. Seats uncomfortable. Food and snacks horrible. Movies were the same as the first 10 hour flight two weeks before

The airline did not allow enough time for the Columbia checkpoint

They should provide water to passengers who ask for it

The worst experience I've ever had because the "people" @ Avianca wouldn't let me fly because they said I needed a round trip ticket

Seating was tight. Seats don't recline. Initial flight was cancelled. Lost two days of vacation.

I had bad experiences before now was excellent I am glad they have business class again

It was delayed and I lost my connection flight to Cali and I missed my Mom's funeral

I actually upgraded to the medium level of seats from basic and even doing that it may have been physically the most uncomfortable flight I have ever had. They packed everyone like is a train to death camp. It was a red eye so I hoped to get some sleep but it was physically impossible to find a comfortable way to rest. I met other folks on the same flight and they said the same thing. It was an utterly miserable flight and if I have any other options I will never fly with them again

Not good, tried to purchase a first class upgrade and they couldn’t get it done. Was super uncomfortable the whole time.

Deplaning was a mess, I sat in business (seats are horrible) and the front door had a problem so we had to deplane from the rear exit. The stairs were not tall enough to reach so there was a large step down from the plane to the top of the stairs.

Staff are the rudest in the industry … awful customer service … will never fly Avianca again

Everything you need to know for your flight from Ontario to Costa Rica

Information on your arrival and departure airports