$241 Cheap Flights from Denver (DEN) to London (LHR)

Popular airlines from Denver Intl. Airport (DEN) to Heathrow Airport (LHR)

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Find available prices by choosing your travel dates.

Cheap Flights from Denver to London (DEN-LHR)

Prices were available within the past 7 days and start at $241 for one-way flights and $517 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Icelandair
British Airways
United
Air Canada
British Airways
Lufthansa
Swiss International Air Lines
Brussels Airlines
JetBlue Airways
Iberia
Flights from Denver (DEN) to London (LHR)
Origin airport
Denver Intl.
Destination airport
Heathrow
Airlines serving
Aer Lingus, Air Canada, Air France, Alaska Airlines, American Airlines, Austrian Airlines, British Airways, Brussels Airlines, Delta, Finnair, Iberia, Icelandair, JetBlue Airways, KLM, Lufthansa, Swiss International Air Lines, Turkish Airlines, United, Virgin Atlantic, WestJet
Roundtrip price
$517
Distance
4658 mi

Denver to London Flights

The cheapest times to fly from Denver 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 Denver to London are during the month of December. You can find some of the cheapest flights from Denver to London with Expedia's search tool and vast selection of airlines.

The best time to book a flight from Denver to London

Sunday is one of the best days to book for cheap flights from Denver 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 Denver 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 Denver to London in 2025. You can also book with separate airlines for your outbound and return journeys, from $241 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 Denver 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 Denver 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 long does it take to fly from Denver Airport to Heathrow Airport?
Book a seat with United Airlines and you’ll be airborne for about 9 hours. This well-known airline operates a direct flight that jets off at 5:40PM from DIA airport and touches down at London Heathrow at 9:40AM. Expedia has some great flight deals, so find out what’s available on this route today.
Is it cheaper to buy a plane ticket from DEN to London Heathrow last minute?
Being a spontaneous soul is a rewarding way to travel the globe, but it isn’t necessarily the wisest method to find a bargain airfare. It’s better to book your DEN to Heathrow Airport (LHR) trip ahead of time instead of leaving it to the last minute. Based on flight pricing and demand studies in 2022, we have found that the best time to book domestic flights is between 28 – 35 days ahead of the departure date, and international flights three to four months in advance. Save all that spontaneity for when you reach Heathrow Airport (LHR)!
What airline has the least delays from DEN to London Heathrow?
If you’d rather not be stuck at your gate for hours — or worse, have your vacation plans ruined due to a flight delay — travel with United Airlines. Around 63% of its Denver Intl. Airport (DEN) to Heathrow Airport (LHR) services arrive on schedule. You can check your flight status before setting out for the airport through the Expedia App. It’ll also provide you with real-time notifications about other useful things, such as changes to your gate number and how to get to your hotel. Everything you need to know is right there in your pocket!
What airports do you fly into for London from Denver?
With Heathrow Airport (LHR), London City Airport (LCY) and Gatwick Airport (LGW) to pick from, traveling from Denver to London is a breeze. The city’s main gateway, Heathrow Airport (LHR), is roughly 14 mi west of the center. Apart from the price of tickets, consider things like train or bus options from the airport and the distance to your hotel when deciding where to touch down. Get your London trip off to an awesome start by visiting Big Ben and Buckingham Palace.
What are the most popular departure times for flights from DIA airport to LHR?
For United Airlines flights from Denver Intl. Airport (DEN) to London Heathrow, the busiest time is between 5:00 PM - 6:00 PM. If you want to avoid any holdups, fly in the morning. This gives you a better chance to avoid the heavy air traffic that builds up as the day goes by.
Can I change the date of my flight from Denver Airport to Heathrow Airport (LHR)?
Quickly make changes to your Denver Airport to London Heathrow journey by logging in to the Expedia Trips portal. But before amending dates or times, check the conditions and rules in your itinerary to learn what you’re able to do and whether fees apply. Some carriers charge a change fee per person, plus any difference in ticket prices. But if you booked in the last 24 hours, you may be able to cancel for free and book new flights. You can also browse our Customer Service portal for more handy information and to chat with our Virtual Agent.

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