Cheap flights from Seattle to London from C$ 316
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 31/7. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
Discover deals from 900+ travel sites with momondo.
Save money when you book flights with momondo
Big names, great deals
Big names, great deals
Search 100s of travel sites to compare prices.Filter for what you want
Filter for what you want
Free Wi-Fi? Early arrival? Instantly customize your resultsTrusted and free
Trusted and free
We’re completely free to use - no hidden charges or fees.Price Alerts
Price Alerts
Not ready to book? to track prices.Find the cheapest flights from Seattle to London
Cheap round-trip flights
Cheap one-way flights
Cheap last-minute flights
Cheap direct flights
Delta flights from Seattle to London
Our best Delta deals on Seattle to London flight tickets
KLM flights from Seattle to London
Our best KLM deals on Seattle to London flight tickets
See travel insights to London from
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?
In general, January is the cheapest month to fly from Seattle to London. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around C$ 916. If you aren’t able to travel to London during the month of January, then flying in October is also cheap. Prices for this month can be found on momondo for an average of C$ 916.
What is the cheapest day to depart on your flight to London?
According to our data, Sunday is the cheapest day to fly to London 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 for around C$ 1,309.
What is the cheapest time of day to depart on your flight to London?
Our most recent data shows that the best time of day to fly to London is in the morning. Flights from Seattle to London during this time can be as low as C$ 935. In the afternoon is when there is more demand to fly to London, so prices are often more expensive at around C$ 1,291 per ticket.
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 9 weeks ahead of your departure date. In general, you can expect to find flights to London 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 from Seattle for as low as C$ 1,012 on momondo.
What cabin class options are available on Seattle/Tacoma Intl to London flights?
There are 3 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.
Can stopping save me money on Seattle to London flights?
You could potentially save up to 54% on your flight if you consider stops on a Seattle to London flight.
How have Seattle to London flight prices changed over time?
As of June 2025, prices for Seattle to London flights are approximately 32% cheaper when compared to flights at the same time last year.
What is the cheapest airline that flies from Seattle/Tacoma Intl to London?
Icelandair, JetBlue, and WestJet are the most popular carriers operating from Seattle/Tacoma Intl to London
Which airlines fly to London?
Virgin Atlantic, British Airways and Iberia are the top three most popular airlines that fly to London 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. Keep in mind that there are 5 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?
21 flights are operational daily from Seattle to London as of June 2025. The most popular departure time for this route is 8:00p.m., with 50% of flights per day taking off in the afternoon.
How many flights depart from Seattle to London on average per week?
As of June 2025, there are 148 flights per week flying from Seattle to London. The most common day of the week flights depart is Mon, with 15% of flights 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?
The straight-line distance from Seattle/Tacoma Intl to London is 7694.7 km. 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?
Prices for flights from Seattle/Tacoma Intl Airport to London are updated daily.
How many operators does momondo search for flights from Seattle/Tacoma Intl Airport to London?
As of June 2025, there are 5 operators available to choose from for flights from Seattle/Tacoma Intl Airport to London.
How old do you have to be to fly from Seattle/Tacoma Intl Airport to London?
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.
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 (25.85% of total bookings). The next most popular plane models are Boeing 777-300ER (22.26%), Airbus A330-900neo (22.01%), and Boeing 777 (9.42%).
What is the most popular airline from Seattle to London?
Based on momondo bookings for this flight route, the most popular airline on flight routes from Seattle to London is Icelandair (26% of total bookings). The next most popular airlines are British Airways (22%), Virgin Atlantic (21%), and Iberia (12%).
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 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
The lowest priced KLM flight from Seattle to London from the last 72 hours was C$ 584. Generally, KLM has 14 flights on this route every week with an average price of C$ 683. KLM is rated 7.8/10 by our users.
Virgin Atlantic Flights From Seattle to London
C$ 573 is the best Virgin Atlantic flight deal from Seattle to London found on momondo over the last 72 hours. The average Virgin Atlantic ticket price found was closer to C$ 736, however, with flight time and availability significantly affecting the price. Virgin Atlantic (7.4/10 from 652 user reviews) flies into London from Seattle 14 times in an average week so prices can vary.
Travelling 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?
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?
momondo helps you find the best flight between Seattle and London by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.
I’m not ready to book a flight from Seattle to London right now. Can momondo alert me if prices change?
Yes. momondo can track prices for Seattle to London flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.