Seattle-Tacoma to Denver International
1022 miles great-circle distance, typically flown in 2h 27m with 8 airlines operating direct service from Seattle-Tacoma (SEA) to Denver International (DEN). Cheapest fares are usually in January (around $169 return), with peak prices in August (around $507). Departures on a Tuesday tend to undercut weekend prices on this corridor.
Flying from Seattle-Tacoma
Seattle-Tacoma is Alaska Airlines' principal hub and Delta's growing Pacific Northwest base. The Link Light Rail Red Line runs from the airport's elevated station directly to Westlake in downtown Seattle in 38 minutes for $3.25 — possibly the easiest big-city transfer in the country. International long-haul has expanded sharply post-2023 with new direct service to Tokyo, Seoul, Frankfurt, London Heathrow and Auckland. Weather delays are rare; SEA is one of the most operationally reliable winter airports in the US.
Arriving in Denver
Denver International is 25 miles northeast of downtown Denver — the most remote big-city airport in the US, deliberately sited to allow for unlimited expansion. The University of Colorado A Line commuter train runs from a dedicated station every 15 minutes to Union Station in 37 minutes for $10.50. Snow can disrupt operations from November through April; Denver fares are cheapest in shoulder seasons (April–May, September–October).
Who flies SEA to DEN?
| Airline | IATA | Flight time | Cabin |
| Alaska Airlines | AS | 2h 27m | Economy |
| Delta Air Lines | DL | 2h 27m | Economy |
| Southwest Airlines | WN | 2h 27m | Economy |
| American Airlines | AA | 2h 27m | Economy |
| United Airlines | UA | 2h 27m | Economy |
| JetBlue Airways | B6 | 2h 27m | Economy |
| Spirit Airlines | NK | 2h 27m | Economy |
| Hawaiian Airlines | HA | 2h 27m | Economy |
8 carriers fly direct on this corridor. Frequencies vary by season — summer and winter holiday peaks see additional flights.
Best time to fly SEA→DEN
Synthesised from 12-month price aggregates. Cheapest months in green, peak in red.
Estimated baseline. Prices update on a 30-day cadence as Travelpayouts data refreshes. Cheapest day-of-week typically Tuesday.
Seattle to Denver FAQs
Direct flights from Seattle-Tacoma (SEA) to Denver International (DEN) take approximately 2h 27m for the 1022-mile journey, plus 30–60 minutes of taxi, climb and descent. Total airport-to-airport time depends on cruise winds and air-traffic queueing on approach.
January is typically the cheapest month on this route, with one-way fares from $169. August is the peak — expect prices 2–3× higher. Book 4–8 weeks ahead for best fares; last-minute prices on this corridor rise sharply inside two weeks of departure.
8 carriers operate direct service from Seattle-Tacoma (SEA) to Denver International (DEN): Alaska Airlines, Delta Air Lines, Southwest Airlines, American Airlines, United Airlines and 3 more. Frequencies vary by season and carrier — Alaska Airlines typically operates the highest weekly count on this corridor.
No — United States is domestic travel for US citizens. A US passport is not required for the 50 states, DC or US territories (Puerto Rico, US Virgin Islands, Guam, American Samoa, Northern Mariana Islands), though Real ID-compliant ID is required at TSA from May 2025.
Denver International (DEN) is the primary international airport for Denver. Allow 30–60 minutes for the ground transfer by train, express bus, taxi or rideshare depending on traffic and time of day. See the airport's official website for current train and shuttle timetables.