£66 Find Cheap Flights from Denver to Seattle – Compare and Save

Among airlines operating Denver to Seattle flights:

• Frontier: offers free seat selection
• Alaska Airlines: offers extra legroom; offers free seat selection
• United Airlines: offers extra legroom; offers free seat selection
• Delta: offers extra legroom; offers free seat selection
• Southwest: offers free seat selection

Extra legroom and free seat selection availability depends on fare class and route.

6 airlines operate flights between Denver and Seattle. The airlines offering direct flights on this route include:

• United Airlines
• Alaska Airlines
• Southwest
• Delta
• Frontier
• American Airlines

Flights from Denver to Seattle usually depart from Denver Intl (DEN) and arrive at Seattle/Tacoma Intl (SEA).

Here are some options for this route, based on selected ticket types and cabin classes:

• Frontier: a cabin bag and a checked bag in Economy class
• Alaska Airlines: a cabin bag and a checked bag in Economy class
• United Airlines: a cabin bag and a checked bag in Economy class

Bag allowance can vary by ticket type, cabin class, route, and airline, so travellers should check the fare details before booking.

Only Economy class is available on flights from Denver to Seattle.

On this route, stopover flights are cheaper than direct options on average. Stopover fares average £148 return via Los Angeles (LAX), compared with £191 for direct.

There is no standard. Checked bag policies vary by airline on this route. Most carriers charge £23–£74 for the first checked bag in Economy. Premium fares and elite status bookings typically include a free checked bag.

The Airbus A321neo family is used most often on this route, operated mainly by United Airlines and Frontier. Other aircraft seen on the route include Boeing 737 MAX 8 variants.

One-stop flights from Denver to Seattle most commonly connect through:

• Las Vegas Harry Reid Intl (LAS) – 29% of one-stop connections
• San Francisco (SFO) – 29% of one-stop connections
• Los Angeles (LAX) – 14% of one-stop connections
• Phoenix Sky Harbor Intl (PHX) – 14% of one-stop connections

Las Vegas Harry Reid Intl (LAS) handles the largest share of one-stop connections on this route.

Yes. Being flexible with your travel dates can save you up to 10% on the Denver to Seattle route. Wednesday is the cheapest departure day at £182 return on average, while Sunday is the most expensive at £202, a difference of £20. KAYAK's flexible dates feature shows options up to 3 days before and after your selected dates, making it easier to compare nearby fares.

A flight is considered delayed when it departs 15 minutes or more after its scheduled time. This is the standard used by the US Department of Transportation and most airline industry reporting. On the Denver to Seattle route, 16% of flights were delayed in the past 3 months, with delays averaging 2 hours 26 minutes.

Morning is the busiest departure period on Denver to Seattle flights, with 36% leaving in that window. Afternoon departures account for 36%, Evening flights for 23%, and Night flights for 5%.

Some of the most popular sights in Seattle are The Westin Seattle, Seattle Center, and Seattle Marriott Waterfront. These are among the most viewed places in Seattle on KAYAK.

These are the earliest and latest flight times available from Denver to Seattle:

• Earliest: departs at 00:25 and lands at 03:29
• Latest: departs at 22:45 and lands at 01:49.

The flight takes about 3h 04m.

Last-minute fares on this route (booked within 2 weeks of departure) run 37% above the route average of £190. Book 6 weeks before departure for the lowest fares.

A direct flight from Denver to Seattle takes 3h 04m, covering 1,022 miles.

No, a passport is not required for this domestic route, but you will need a real ID-compliant driver's license, a state ID, or another TSA-accepted form of identification.

Yes. Based on fares seen in the past 5 days, return flight prices on this route showed a wide range, from about £116 to £682. That means the highest observed fare was about 6x higher than the lowest one.

One-way fares from Denver to Seattle are currently lower than usual. Average one-way flight prices are about £76, which is 43% below the typical average for this route.

Frontier is slightly above the route average for timely arrivals, while United Airlines has a lower on-time arrival rate. On-time arrival rates on Denver to Seattle flights are:

• Frontier: 90% on time
• United Airlines: 88% on time
• Delta: 87% on time

On average, flights on this route are punctual 84% of the time.

Morning flights have the fewest delays on this route. Delays tend to pile up throughout the day as one late flight pushes the next, so earlier departures are usually more reliable.

Flying via Phoenix Sky Harbor Intl (PHX) gives the shortest average 1-stop total travel time of 5h 57m, compared to 5h 58m via Salt Lake City (SLC) and 6h 33m via San Francisco (SFO).

Seattle is 1 hour behind Denver (Pacific Time vs Mountain Time). Plan for the time shift when scheduling connections or first-day activities.

Seattle/Tacoma Intl Airport (SEA) hosts 5 major car hire companies, with daily rates starting from around £3 for economy cars. Top options include:
• Fox
• Europcar
• Thrifty
• Budget
• Dollar

Return flights from Denver to Seattle range from £129 to £250, with an average of £190 over the past 12 months. Anything below £129 counts as a good deal.

Four airlines offer in-flight Wi-Fi on Denver to Seattle flights:

• • Alaska Airlines
• • Delta
• • JetBlue
• • American Airlines