Cheap Flights Denver to Seattle from £23

Flight FAQs

• Which airlines offer the cheapest flights from Denver to Seattle?

  Based on Trip.com data, Frontier Airlines offers Cheapest nonstop one-way flights from £23 (for example, DEN–SEA on Thu, Nov 26). For a Cheapest nonstop return flight, Frontier Airlines offers fares from £53, departing on Wed, Dec 2 and returning on Mon, Dec 7.

• Which airlines offer direct flights from Denver to Seattle?

  At the moment, you can catch a direct flight from Denver to Seattle with the following airlines, including: Frontier Airlines Delta Air Lines Selected airlines are based on historical data collected from flight bookings users made on Trip.com within the last 90 days.

• How long is a flight from Denver to Seattle?

  A flight from Denver (DEN) to Seattle (SEA) takes an average of 3 hours 17 minutes.

• When is the best time to book flights from Denver to Seattle?

  By analyzing data from all airlines on the Trip.com flight calendar, it looks like the best time to book a flight from Denver to Seattle is around 40 days (6 weeks) in advance, and the best time to fly is usually on Tuesday, Wednesday, and Saturday. Tuesday typically offers the cheapest flights for departure, while Saturday offers the best return deals.

• How many flights are there from Denver to Seattle each week?

  On average, 60 direct flights operate each week between Denver and Seattle. See below the schedules of the main airlines serving this route:
  Delta Air Lines: S/M/T/W/T/F/S – DL1731 (departure at 06:06)

• How can I find the best deals on flights from Denver to Seattle?

  Here are some tips for finding the best flight deals from Denver to Seattle on Trip.com:
  · Be flexible with your travel dates. The cheapest flight is currently on Thu, Nov 26, with one-way fares from just £23.
  · Compare airlines. Frontier Airlines currently offers the lowest fares on this route.
  · Set up a price alert to track fare changes without searching every day.
  · Check Trip.com regularly for flight deals and available promo codes.
  · Avoid peak season or book early. January is generally the busiest month for travel to Seattle.
  · Get exclusive promo codes on the Trip.com app.

• When is the best time to book a flight from Denver to Seattle to get the best price?

  The cheapest month to book a flight from Denver to Seattle is usually October, when demand is lower.

• Which upcoming date is the cheapest for flights from Denver to Seattle?

  After crunching the numbers on our October flight calendar, it's currently cheapest to fly from Denver to Seattle on October 24, 2026 with Frontier Airlines, with prices starting at £18.

• Which airports should you choose for flights from Denver to Seattle?

  Flights to Seattle can arrive at: King County (Boeing Field) International Airport (BFI), Kenmore Air Harbor Seaplane Base (LKE) and Seattle-Tacoma International Airport (SEA). The most common route connects Denver International Airport and Seattle-Tacoma International Airport (DEN–SEA).

• What is the time difference between Denver and Seattle?

  The time difference between Seattle and Denver is 1h.

• How can I change or cancel my flight ticket from Denver to Seattle?

  Tickets can only be changed or cancelled if permitted by airline policy. To submit a change or cancellation request, go to the flight bookings page, select the option to change or cancel your booking, choose the relevant passengers and segment, and submit a request. Please note that additional charges may apply according to the airline ticket policy. However, if the flight has been rescheduled and you would like to change or cancel your ticket, you can submit an involuntary cancellation request. For more details about change and cancellation policies, please check the customer support pages.

• What is the average price of a one-way flight from Denver to Seattle?

  Based on Trip.com data for flights departing in the next 30 days, the average one-way fare from Denver to Seattle is £138. Fares vary by travel date, airline and availability.

• What is the average price of a return flight from Denver to Seattle?

  Based on Trip.com data for flights departing in the next 30 days, the average return fare from Denver to Seattle is £229. Fares vary by travel date, airline and availability.

• How do I book flights from Denver to Seattle on Trip.com?

  Enter Denver and Seattle, choose your travel dates and passengers, then compare flights by price, duration and baggage. Select a fare, review the change and cancellation rules, enter traveller details and complete payment to receive your confirmation.

• Are there budget airlines on the Denver to Seattle route?

  Frontier Airlinesare the most popular budget airlines flying from Denver to Seattle. Check baggage, seat and payment fees before comparing the final price.