$331 Cheap Flights from St. Louis (STL) to London (YXU)

Popular airlines from St. Louis Lambert Intl. Airport (STL) to London, ON (YXU-London Intl.)

Find available prices by choosing your travel dates.

Cheap Flights from St. Louis to London (STL-YXU)

Prices were available within the past 7 days and start at $331 for one-way flights and $636 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

United
United
United
Air Canada
United
United
Air Canada
Air Canada
United
WestJet
Flights from St. Louis (STL) to London (YXU)
Origin airport
Lambert-St. Louis Intl.
Destination airport
London Intl.
Roundtrip price
$636
Distance
564 mi

St. Louis to London Flights

The cheapest times to fly from St. Louis to London

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 St. Louis to London are during the month of May. You can find some of the cheapest flights from St. Louis to London with Expedia's search tool and vast selection of airlines.

The best time to book a flight from St. Louis to London

Sunday is one of the best days to book for cheap flights from St. Louis to London: 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 St. Louis to London

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 St. Louis to London in 2025. You can also book with separate airlines for your outbound and return journeys, from $331 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 St. Louis to London 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 St. Louis to London 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 Lambert-St. Louis Intl. Airport (STL) to London Intl. Airport (YXU) cost?
Discover the latest flight deals from STL to YXU 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 STL to YXU?
The cheapest flights from STL to YXU 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 STL to YXU?
Use the filter tool on Expedia to compare airlines and find the cheapest carrier that’ll take you from STL to YXU. Sort your results by “Price (lowest to highest)” to snap up a great deal.
How many flights per day from Lambert-St. Louis Intl. Airport (STL) to London Intl. Airport (YXU)?
You’ll have to take a flight with a layover when traveling from Lambert-St. Louis Intl. Airport (STL) to London Intl. Airport (YXU). Direct flights don’t operate daily on this route. However, simply filter your search to include one or two stops to find the best option for your trip.
What day of the week has the most flights from STL to YXU?
You’ll generally find Tuesday the quietest day for flights, while Fridays tend to be the busiest.* However this can vary from season to season and during peak travel times or public holidays.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Lambert-St. Louis Intl. Airport (STL) to London Intl. Airport (YXU)?
To reach London Intl. Airport (YXU) on schedule, opt for a flight that takes off from Lambert-St. Louis Intl. Airport (STL) before 3 PM. The chance of cancellations is 22% higher, on average, for departures after this hour.**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 Lambert-St. Louis Intl. Airport (STL) to London Intl. Airport (YXU) last-minute?
Waiting until just before your trip to book a flight from STL to YXU generally means paying more. Although you may find some last-minute offers, they’re not always guaranteed. Keep your travel plans flexible for a better chance of landing a bargain.
Is it cheaper to book a STL to YXU flight and hotel package?
Compared with arranging hotels and flights separately, booking a STL to YXU flight and hotel package with Expedia could lead to significant savings. What’s more, having everything in one easy place will take the hassle out of travel planning. Just secure your flights and choose from our extensive range of hotels, then tailor your trip with extras like tours, activities and car rentals.
Can I cancel or change the date of my flight from Lambert-St. Louis Intl. Airport (STL) to London Intl. Airport (YXU)?
If you booked your STL to YXU flight within the last 24 hours, you may be able to cancel or modify it without any fees. Depending on the airline and the type of fare you purchased, additional charges may apply for changes beyond that time. Airline policies and contact information can be found in your itinerary or confirmation email. Or, go to our Customer Service portal for more information.

Explore a world of travel with Expedia

*Available to One Key members.