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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Scandinavian Airlines flights from Seattle to London Heathrow Airport
Our best Scandinavian Airlines deals on Seattle to London Heathrow Airport flight tickets
Air Canada flights from Seattle to London Heathrow Airport
Our best Air Canada deals on Seattle to London Heathrow Airport flight tickets
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How to get the cheapest flight ticket from Seattle to London Heathrow Airport
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 cheapest month to fly to London Heathrow Airport?
The month of March is, on average, the cheapest month to fly to London Heathrow Airport from Seattle, with most prices found around $684. If you’re not able to fly to London Heathrow Airport in March, then April is your next best option. Flight prices from Seattle to London Heathrow Airport during April average around $696.
What is the cheapest day to depart on your flight to London Heathrow Airport?
Our data shows that Tuesday is the least expensive day to fly to London Heathrow Airport. Tickets to fly out on this day can be as low as $819. The most expensive day to fly to London Heathrow Airport is Saturday, with ticket prices averaging around $950.
What is the cheapest time of day to depart on your flight to London Heathrow Airport?
According to our data, the cheapest time of day to fly to London Heathrow Airport is in the evening. momondo users have found flights departing from Seattle to London Heathrow Airport in the evening for as low as $862. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights in the morning are often more expensive with an average ticket price of $987.
What is the cheapest Seattle/Tacoma Intl to London Heathrow flight route?
Fly from Seattle/Tacoma Intl to London Heathrow for the best Seattle/Tacoma Intl - London Heathrow flight prices
How far in advance should I book a flight to London Heathrow Airport?
You are more likely to see cheaper flights to London Heathrow Airport from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to London Heathrow Airport 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 Heathrow Airport from Seattle for as low as $742 on momondo.
What cabin class options are available on Seattle/Tacoma Intl to London Heathrow flights?
There are 4 cabin classes available to choose from on Seattle/Tacoma Intl to London Heathrow 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 Heathrow?
Icelandair is the most popular carrier operating from Seattle/Tacoma Intl to London Heathrow
What airlines fly to London Heathrow Airport?
British Airways, Delta and Virgin Atlantic are the top three most popular airlines that fly to London Heathrow Airport 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 Heathrow Airport. Keep in mind that there are 15 different airlines that fly to London Heathrow Airport on a routine basis, so you have a few additional options to choose from.
How many flights depart from Seattle to London Heathrow Airport on average per day?
As of July 2025, 21 flights take off from Seattle and land in London Heathrow Airport 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 Heathrow Airport on average per week?
148 flights are operational weekly from Seattle to London Heathrow Airport 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 Heathrow Airport
Cheap Seattle to London Heathrow Airport (SEA to LHR) flight deals and tips
Find info about flight duration, direct flights, and airports for your flight from Seattle to London Heathrow Airport
How far is Seattle/Tacoma Intl to London Heathrow by plane?
The straight-line distance from Seattle/Tacoma Intl to London Heathrow is 4774.1 mi. 9h 20m is a normal flight duration for this route.
When did momondo last update prices for flights from Seattle/Tacoma Intl Airport to London Heathrow Airport?
Prices for flights from Seattle/Tacoma Intl Airport to London Heathrow Airport are refreshed on a daily basis.
How many operators does momondo search for flights from Seattle/Tacoma Intl Airport to London Heathrow Airport?
The number of operators available for flights from Seattle/Tacoma Intl Airport to London Heathrow Airport is 15 as of July 2025.
How old do you have to be to fly from Seattle/Tacoma Intl Airport to London Heathrow Airport?
The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Seattle/Tacoma Intl Airport to London Heathrow Airport.
What documentation or ID do you need to fly to London Heathrow Airport?
The travel and health documents you'll need for your trip to London Heathrow Airport 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 Heathrow Airport. 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 Heathrow Airport?
Based on momondo bookings for flights between Seattle and London Heathrow Airport, the leading plane model is Boeing 787-10 Dreamliner, making up 27.46% of the total bookings. Other popular models include Boeing 777-300ER with 23.92%, Airbus A330-900neo with 18.81%, and Boeing 777-300 with 9.31%.
What is the most popular airline from Seattle to London Heathrow Airport?
Based on momondo bookings for this flight route, the most popular airline on flight routes from Seattle to London Heathrow Airport is British Airways (26% of total bookings). The next most popular airlines are Delta (23%), Virgin Atlantic (14%), and Iberia (11%).
Best airlines flying from Seattle to London Heathrow Airport
Compare and see reviews for airlines that fly from Seattle to London Heathrow Airport 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 Heathrow Airport
Delta is one of the most popular airlines flying from Seattle to London Heathrow Airport, operating 14 flights/week on average for this route. A good Delta flight deal for Seattle to London Heathrow Airport starts from $614 round-trip, up to an average price of $863. Our users have rated Delta at 8.0/10.
Alaska Airlines Flights From Seattle to London Heathrow Airport
Another popular option for Seattle to London Heathrow Airport flights is Alaska Airlines (8.0/10, 10,000 ratings). Alaska Airlines flies from Seattle to London Heathrow Airport around 13 times per week, with deals starting from $800 round-trip and rising to an average price of around $999.
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Why should I use momondo to find a flight deal from Seattle to London?
Finding the right flight to London from Seattle is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to London quick and easy, saving you time and money.
Can I find flights from Seattle to London with flexible booking policies on momondo?
Flights from Seattle to London with flexible booking policies can be found by using the search form above and then selecting our dedicated flexible booking filter, which will highlight only the flights where this policy is applied.
How can momondo help me find flights from Seattle to London?
Once you have performed a search for Seattle to London flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.
I’m not ready to book a flight from Seattle to London right now. Can momondo alert me if prices change?
Price alerts on flights to London from Seattle are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.