Cheap flights from Seattle to London from $173
This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Seattle to London departing on 10/13. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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How to get the cheapest flight ticket from Seattle to London
Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip
What is the typical price of a round-trip flight between Seattle and London?
What is the cheapest month to fly to London?
The cheapest month to fly to London from Seattle is in October. Flight prices, which tend to average around $667, are often lower during this time because this is during the off-season. The month of January is another great option to travel to London, with average flight prices from Seattle averaging around $670.
What is the cheapest day to depart on your flight to London?
The cheapest day to depart from Seattle to London is on a Tuesday. Travelers who choose to depart for London on a Tuesday will often find tickets for as low as $819. If your travel schedule is flexible, try to avoid departing on a Saturday because tickets tend to average around $950. These prices are subject to change though, so be sure to set up a Price Alert for flights to London.
What is the cheapest time of day to depart on your flight to London?
Flying to London from Seattle in the evening is the least expensive time of day to depart. momondo users have found prices as low as $862 when looking at flights departing in the evening. Flights to London are more costly in the morning, with an average ticket price of $980. Departure times in the morning fall within the peak daily travel times, which is why tickets can be more expensive.
What is the cheapest Seattle/Tacoma Intl to London flight route?
Fly from Seattle/Tacoma Intl to London Heathrow for the best Seattle/Tacoma Intl - London flight prices
How far in advance should I book a flight to London?
You are more likely to see cheaper flights to London from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to London for around $812 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to London from Seattle for as low as $742 on momondo.
What cabin class options are available on Seattle/Tacoma Intl to London flights?
There are 4 cabin classes available to choose from on Seattle/Tacoma Intl to London flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.
What is the cheapest airline that flies from Seattle/Tacoma Intl to London?
Icelandair is the most popular carrier operating from Seattle/Tacoma Intl to London
What airlines fly to London?
British Airways, Delta and Virgin Atlantic are the top three most popular airlines that fly to London from Seattle according to our data. British Airways is the first choice among our users, with 35% of people opting to fly with this airline when traveling to London. Keep in mind that there are 15 different airlines that fly to London on a routine basis, so you have a few additional options to choose from.
How many flights depart from Seattle to London on average per day?
As of July 2025, 21 flights take off from Seattle and land in London each day. The most common flight departure time for this route is 8:00PM, with 51% of daily flights taking off in the evening.
How many flights depart from Seattle to London on average per week?
148 flights are operational weekly from Seattle to London as of July 2025. The most popular departure day for this route is Mon, with 15% of flights per week taking off on this day.
When to book flights from Seattle to London
Cheap Seattle to London (SEA to LON) flight deals and tips
Find info about flight duration, direct flights, and airports for your flight from Seattle to London
How far is Seattle/Tacoma Intl to London by plane?
London is 4781.3 mi away from Seattle/Tacoma Intl. By plane, this route typically takes 9h 20m.
When did momondo last update prices for flights from Seattle/Tacoma Intl Airport to London?
Prices for flights from Seattle/Tacoma Intl Airport to London are refreshed on a daily basis.
How many operators does momondo search for flights from Seattle/Tacoma Intl Airport to London?
The number of operators available for flights from Seattle/Tacoma Intl Airport to London is 15 as of July 2025.
How old do you have to be to fly from Seattle/Tacoma Intl Airport to London?
The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Seattle/Tacoma Intl Airport to London.
What documentation or ID do you need to fly to London?
The travel and health documents you'll need for your trip to London may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at London. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.
What is the most popular plane model from Seattle to London?
Based on momondo bookings for this flight route, the most popular plane model on flight routes from Seattle to London is Boeing 787-10 Dreamliner (27.46% of total bookings). The next most popular plane models are Boeing 777-300ER (23.92%), Airbus A330-900neo (18.81%), and Boeing 777-300 (9.31%).
What is the most popular airline from Seattle to London?
Based on momondo bookings for flights between Seattle and London, the leading airline is British Airways, making up 21% of the total bookings. Other popular airlines include Delta with 21%, Icelandair with 16%, and Virgin Atlantic with 13%.
Best airlines flying from Seattle to London
Compare and see reviews for airlines that fly from Seattle to London with momondo
| Airline | Rating | Free Cancellation | Price | ||
|---|---|---|---|---|---|
| PriceFrom $378 | Free Cancellation | Rating 6.8 7,207 reviews | |||
| PriceFrom $498 | Free Cancellation | Rating 7.4 8,861 reviews | |||
| PriceFrom $506 | Free Cancellation | Rating 7.0 514 reviews | |||
| PriceFrom $532 | Free Cancellation | Rating 7.3 1,416 reviews | |||
| PriceFrom $556 | Free Cancellation | Rating 7.6 1,306 reviews | |||
| PriceFrom $579 | Free Cancellation | Rating 7.0 2,820 reviews | |||
| PriceFrom $583 | Free Cancellation | Rating 7.1 1,144 reviews | |||
| PriceFrom $597 | Free Cancellation | Rating 7.5 1,465 reviews | |||
| PriceFrom $597 | Free Cancellation | Rating 7.8 1,367 reviews | |||
| PriceFrom $605 | Free Cancellation | Rating 6.6 7,093 reviews |
Delta Flights From Seattle to London
Delta flight deals from Seattle to London start from $614 round-trip. Over the 14 Delta flights for this route in a normal week, average airfare is usually $863 round-trip - but some users have found much cheaper deals with momondo.
Alaska Airlines Flights From Seattle to London
Across 10,000 Alaska Airlines reviews on momondo, the average score is 8.0/10. Alaska Airlines flies from Seattle to London about 13 times each week, with ticket deals ranging from $800 to $999. Price data is based on momondo searches in the last 72 hours.
Traveling to a place near London?
Book flights to London if you plan to visit one of these locationsWhy use momondo?
Why should I use momondo to find a flight deal from Seattle to London?
momondo collates all your flight options in one place and lets you filter them to find the perfect flight from Seattle to London. momondo saves you time and could save you money on your trip.
Can I find flights from Seattle to London with flexible booking policies on momondo?
Yes. All flights to London from Seattle on momondo can be compared and filtered by various policies on offer, including flexible booking.
How can momondo help me find flights from Seattle to London?
momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from Seattle to London.
I’m not ready to book a flight from Seattle to London right now. Can momondo alert me if prices change?
If you are simply researching potential flights to London, momondo offers a useful price alert feature which will track prices for flights to London from Seattle and alert you when they change.