$274 Cheap Flights from Ontario (ONT) to St. Thomas (STT)

View $274 flight on Sun, Sep 28, 2025Opens in a new window

Popular airlines from Los Angeles - Ontario Intl. Airport (ONT) to Cyril E. King Airport (STT)

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Cheap Flights from Ontario to St. Thomas (ONT-STT)

Prices were available within the past 7 days and start at $274 for one-way flights and $531 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

JetBlue Airways
Sun, Sep 14 - Fri, Sep 19
ONT
Ontario
STT
St. Thomas
$531 Roundtrip, found 18 hours ago
$531
Roundtrip
found 18 hours ago
Select JetBlue Airways flight, departing Sun, Sep 14 from Ontario to St. Thomas, returning Fri, Sep 19, priced at $531 found 18 hours ago
JetBlue Airways
Sat, Sep 20 - Mon, Sep 22
ONT
Ontario
STT
St. Thomas
$551 Roundtrip, found 18 hours ago
$551
Roundtrip
found 18 hours ago
Select JetBlue Airways flight, departing Sat, Sep 20 from Ontario to St. Thomas, returning Mon, Sep 22, priced at $551 found 18 hours ago
JetBlue Airways
Sat, Oct 4 - Thu, Oct 9
ONT
Ontario
STT
St. Thomas
$573 Roundtrip, found 1 day ago
$573
Roundtrip
found 1 day ago
Select JetBlue Airways flight, departing Sat, Oct 4 from Ontario to St. Thomas, returning Thu, Oct 9, priced at $573 found 1 day ago
JetBlue Airways
Sat, Sep 13 - Fri, Sep 19
ONT
Ontario
STT
St. Thomas
$577 Roundtrip, found 18 hours ago
$577
Roundtrip
found 18 hours ago
Select JetBlue Airways flight, departing Sat, Sep 13 from Ontario to St. Thomas, returning Fri, Sep 19, priced at $577 found 18 hours ago
JetBlue Airways
Sun, Sep 28 - Sun, Oct 5
ONT
Ontario
STT
St. Thomas
$583 Roundtrip, found 6 hours ago
$583
Roundtrip
found 6 hours ago
Select JetBlue Airways flight, departing Sun, Sep 28 from Ontario to St. Thomas, returning Sun, Oct 5, priced at $583 found 6 hours ago
American Airlines
Sun, Oct 5 - Thu, Oct 9
ONT
Ontario
STT
St. Thomas
$595 Roundtrip, found 4 hours ago
$595
Roundtrip
found 4 hours ago
Select American Airlines flight, departing Sun, Oct 5 from Ontario to St. Thomas, returning Thu, Oct 9, priced at $595 found 4 hours ago
Delta
Sun, Oct 5 - Thu, Oct 9
ONT
Ontario
STT
St. Thomas
$595 Roundtrip, found 4 hours ago
$595
Roundtrip
found 4 hours ago
Select Delta flight, departing Sun, Oct 5 from Ontario to St. Thomas, returning Thu, Oct 9, priced at $595 found 4 hours ago
United
Sat, Sep 27 - Sat, Oct 4
ONT
Ontario
STT
St. Thomas
$595 Roundtrip, found 11 hours ago
$595
Roundtrip
found 11 hours ago
Select United flight, departing Sat, Sep 27 from Ontario to St. Thomas, returning Sat, Oct 4, priced at $595 found 11 hours ago
American Airlines
Wed, Dec 3 - Mon, Dec 8
ONT
Ontario
STT
St. Thomas
$600 Roundtrip, found 6 hours ago
$600
Roundtrip
found 6 hours ago
Select American Airlines flight, departing Wed, Dec 3 from Ontario to St. Thomas, returning Mon, Dec 8, priced at $600 found 6 hours ago
American Airlines
Sun, Sep 28 - Sun, Oct 5
ONT
Ontario
STT
St. Thomas
$606 Roundtrip, found 6 hours ago
$606
Roundtrip
found 6 hours ago
Select American Airlines flight, departing Sun, Sep 28 from Ontario to St. Thomas, returning Sun, Oct 5, priced at $606 found 6 hours ago

Find the cheapest month to fly from Ontario (ONT) to St. Thomas (STT)

September is typically the cheapest month to fly

From $461 - $867 per traveler.

Graph displaying average flight prices per month

Alternative airports near St. Thomas

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Cyril E. King STT. Cheapest option available. Flights from $894
STT
Cyril E. King
Cheapest
Flights from $894
Flights from Ontario (ONT) to St. Thomas (STT)
Origin airport
Los Angeles - Ontario Intl.
Destination airport
Cyril E. King
Airlines serving
American Airlines, Delta, JetBlue Airways, United
Roundtrip price
$531
Distance
3398 mi

Ontario to St. Thomas Flights

The cheapest times to fly from Ontario to St. Thomas

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Ontario to St. Thomas are during the month of September. You can find some of the cheapest flights from Ontario to St. Thomas with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Ontario to St. Thomas

Sunday is one of the best days to book for cheap flights from Ontario to St. Thomas: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Ontario to St. Thomas

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Ontario to St. Thomas in 2025. You can also book with separate airlines for your outbound and return journeys, from $274 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Ontario to St. Thomas flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Ontario to St. Thomas airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from Los Angeles - Ontario Intl. Airport (ONT) to Cyril E. King Airport (STT) cost?
Discover the latest flight deals from ONT to STT by entering your preferred travel dates and searching on Expedia. Easily compare prices by departure date if you have flexibility with your schedule and use handy filters to explore prices for your preferred journey. As a member of One Key™, our free loyalty program, you can use Price Tracking to watch fares and receive notifications if prices go up or down.
What is the cheapest month to fly from ONT to STT?
The cheapest flights from ONT to STT are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
What is the cheapest airline that flies from ONT to STT?
Use the filter tool on Expedia to compare airlines and find the cheapest carrier that'll take you from ONT to STT. Sort your results by "Price (lowest to highest)" to snap up a great deal.
How many flights per day from Los Angeles - Ontario Intl. Airport (ONT) to Cyril E. King Airport (STT)?
There are no daily nonstop flights available from Los Angeles - Ontario Intl. Airport (ONT) to Cyril E. King Airport (STT). But you can choose flights with layovers. Filter your search results on Expedia to include one or more stops, and you'll be soaring above the clouds before you know it.
What day of the week has the most flights from ONT to STT?
Friday is generally the busiest day for flights, while Tuesday is often the quietest.* Just remember that flight schedules can change depending on a range of factors, including the season and airline.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Los Angeles - Ontario Intl. Airport (ONT) to Cyril E. King Airport (STT)?
To avoid possible delays on the Los Angeles - Ontario Intl. Airport (ONT) to Cyril E. King Airport (STT) route, aim to travel before 3 PM. Later departures have a 22% higher chance of being canceled.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
Is it cheaper to buy a plane ticket from Los Angeles - Ontario Intl. Airport (ONT) to Cyril E. King Airport (STT) last-minute?
Booking your flight from ONT to STT right before your trip is typically more expensive. But if there's some wiggle room with your travel dates and times, you could score a cheap last-minute fare.
Is it cheaper to book an ONT to STT flight and hotel package?
Opting for an ONT to STT flight and hotel package is usually cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your travels in one place. Pick from our impressive range of hotels and then add activities, flights and car rentals to your booking. Bundle it all together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Los Angeles - Ontario Intl. Airport (ONT) to Cyril E. King Airport (STT)?
Generally, it's possible to reschedule or cancel your ONT to STT flight. However, for bookings made more than 24 hours ago, additional charges may apply. Refer to your airline's policies in your itinerary to see what changes are possible and whether any costs are involved. You'll also find further details on our Customer Service portal.

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*Available to One Key members.