Cheap flights from Seattle to London from C$ 328
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 27/7. 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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Delta flights from Seattle to London Heathrow Airport
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KLM flights from Seattle to London Heathrow Airport
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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 C$ 935. If you aren’t able to travel to London Heathrow Airport during the month of March, then flying in April is also cheap. Prices for this month can be found on momondo for an average of C$ 952.
What is the cheapest day to depart on your flight to London Heathrow Airport?
According to our data, Sunday is the cheapest day to fly to London Heathrow Airport from Seattle. The lowest ticket price found for a Sunday departure recently was C$ 1,213. Keep in mind that prices can always vary depending on your route and whether or not you are flying domestic or international. When flying out on a Friday, the most expensive travel day of the week, you can expect to see flight prices from Seattle to London Heathrow Airport for around C$ 1,309.
What is the cheapest time of day to depart on your flight to London Heathrow Airport?
Our data shows that the cheapest Seattle to London Heathrow Airport flights are usually those with departure times in the morning. Our users have found flights to London Heathrow Airport in the morning for as low as C$ 930. In the afternoon is when there is more demand to fly to London Heathrow Airport, so prices are often more expensive at around C$ 1,291 per ticket.
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 9 weeks ahead of your departure date. In general, you can expect to find flights to London Heathrow Airport for around C$ 1,111 when searching 9 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 C$ 1,012 on momondo.
What cabin class options are available on Seattle/Tacoma Intl to London Heathrow flights?
There are 3 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.
Can stopping save me money on Seattle to London Heathrow Airport flights?
You could potentially save up to 54% on your flight if you consider stops on a Seattle to London Heathrow Airport flight.
How have Seattle to London Heathrow Airport flight prices changed over time?
As of June 2025, prices for Seattle to London Heathrow Airport flights are approximately 0% cheaper when compared to flights at the same time last year.
What is the cheapest airline that flies from Seattle/Tacoma Intl to London Heathrow?
Icelandair, WestJet, and JetBlue are the most popular carriers operating from Seattle/Tacoma Intl to London Heathrow
Which airlines fly to London Heathrow Airport?
Virgin Atlantic, British Airways and Iberia are the top three most popular airlines that fly to London Heathrow Airport from Seattle according to our data. Virgin Atlantic is the first choice among our users, with 40% of people opting to fly with this airline when travelling to London Heathrow Airport. Keep in mind that there are 5 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 June 2025, there are 21 flights per day flying from Seattle to London Heathrow Airport. The most common time of day flights depart is 8:00p.m., with 50% of flights taking off in the afternoon.
How many flights depart from Seattle to London Heathrow Airport on average per week?
The number of flights available between Seattle and London Heathrow Airport is 148 per week as of June 2025. The most frequent departure day is Mon, with 15% of weekly flights leaving 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?
London Heathrow is 7683.2 km away from Seattle/Tacoma Intl. A reasonable flight in good conditions will take 9h 20m.
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 updated daily.
How many operators does momondo search for flights from Seattle/Tacoma Intl Airport to London Heathrow Airport?
As of June 2025, there are 5 operators available to choose from for flights from Seattle/Tacoma Intl Airport to London Heathrow Airport.
How old do you have to be to fly from Seattle/Tacoma Intl Airport to London Heathrow Airport?
Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify 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?
momondo data reveals that the most frequently booked plane model on the route from Seattle to London Heathrow Airport is Boeing 787-10 Dreamliner, representing 25.85% of all bookings. The subsequent popular models are Boeing 777-300ER at 22.26%, Airbus A330-900neo at 22.01%, and Boeing 777 at 9.42%.
What is the most popular airline from Seattle to London Heathrow Airport?
Based on momondo bookings for flights between Seattle and London Heathrow Airport, the leading airline is Virgin Atlantic, making up 36% of the total bookings. Other popular airlines include British Airways with 23%, Iberia with 16%, and Icelandair with 15%.
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 C$ 603 | Free Cancellation | Rating 7.0 499 reviews | |||
| PriceFrom C$ 624 | Free Cancellation | Rating 7.0 2,776 reviews | |||
| PriceFrom C$ 743 | Free Cancellation | Rating 6.6 7,008 reviews | |||
| PriceFrom C$ 784 | Free Cancellation | Rating 7.4 652 reviews | |||
| PriceFrom C$ 798 | Free Cancellation | Rating 7.8 1,358 reviews |
KLM Flights From Seattle to London Heathrow Airport
KLM operates around 14 flights from Seattle to London Heathrow Airport every week. The average price of these flights found in the last 72 hours has been C$ 683, but momondo users have found KLM deals from Seattle to London Heathrow Airport from as low as C$ 584 round-trip. KLM has been scored 7.8/10 in 1,358 reviews.
Virgin Atlantic Flights From Seattle to London Heathrow Airport
Another popular option for Seattle to London Heathrow Airport flights is Virgin Atlantic (7.4/10, 652 ratings). Virgin Atlantic flies from Seattle to London Heathrow Airport around 14 times per week, with deals starting from C$ 573 round-trip and rising to an average price of around C$ 736.
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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?
All flight searches from Seattle to London on momondo can be filtered to show those which offer flexible booking policies.
How can momondo help me find flights from Seattle to London?
Once all potential Seattle to London flight options are in front of you, momondo lets you sort and filter flights based on preferences such as airline, price and flight times amongst many other options.
I’m not ready to book a flight from Seattle to London right now. Can momondo alert me if prices change?
Of course. momondo tracks the price of Seattle to London flights. All you need is a valid email address and we will do the rest; it is that quick and easy.