SEA - DEN

C$ 110 Find Cheap Flights from Seattle to Denver – Compare and Save

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Everything you should know

Cheapest round-trip
C$ 192
Typical prices: C$ 233-C$ 469
Frontier
Fri 26/10Fri 2/11
SEA - DEN • Direct
Cheapest one-way flights
C$ 110
Typical prices: C$ 164-C$ 336
Alaska Airlines
Wed 10/10
SEA - DEN • Direct
Direct flights
You can fly direct with United Airlines, Alaska Airlines, and others. Average duration is 2h 46m.
Direct flights
+1
Direct flights
+1
Avoid delays
Most punctual • 92% on-time
Best time • Fewest delays
Insights
Insights
When to book
in advance
Our data shows that travellers who book at least 5 weeks in advance save around 45% compared to booking last minute.
Insights
Insights
When to travel
Cheapest • 36% price drop
Most popular
Good to know
+1
Good to know
+1
Top layover airports
Cheapest • Avg C$ 277 (round-trip)
Shortest trip • 7h 38m (one-way)
Insights
Insights
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We hope you enjoy your trip to Denver!
Flight Deals
Booking Insights
Expert advice
Flight Deals

Cheap Flights from Seattle to Denver (SEA-DEN)

 
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Seattle to Denver

Mon, 26 Oct - Mon, 2 Nov
Frontier Logo
4:27 p.m. - 8:17 p.m.SEA  Seattle/Tacoma Intl-DEN Denver Intl
2h 50mdirect
Frontier Logo
1:04 p.m. - 3:12 p.m.DEN  Denver Intl-SEA Seattle/Tacoma Intl
3h 08mdirect
C$ 192Frontier
Wed, 21 Oct - Sun, 1 Nov
Multiple Airlines Logo
4:27 p.m. - 8:17 p.m.SEA  Seattle/Tacoma Intl-DEN Denver Intl
2h 50mdirect
Multiple Airlines Logo
7:03 a.m. - 9:07 a.m.DEN  Denver Intl-SEA Seattle/Tacoma Intl
3h 04mdirect
C$ 204Multiple Airlines
Fri, 30 Oct - Fri, 30 Oct
Southwest Logo
5:50 a.m. - 9:30 a.m.SEA  Seattle/Tacoma Intl-DEN Denver Intl
2h 40mdirect
Southwest Logo
6:30 p.m. - 8:35 p.m.DEN  Denver Intl-SEA Seattle/Tacoma Intl
3h 05mdirect
C$ 218Southwest
Fri, 4 Dec - Mon, 7 Dec
Southwest Logo
9:25 a.m. - 1:00 p.m.SEA  Seattle/Tacoma Intl-DEN Denver Intl
2h 35mdirect
Southwest Logo
3:40 p.m. - 5:50 p.m.DEN  Denver Intl-SEA Seattle/Tacoma Intl
3h 10mdirect
C$ 218Southwest
Wed, 28 Oct - Sun, 1 Nov
Alaska Airlines Logo
1:16 p.m. - 4:59 p.m.SEA  Seattle/Tacoma Intl-DEN Denver Intl
2h 43mdirect
Alaska Airlines Logo
7:03 a.m. - 9:07 a.m.DEN  Denver Intl-SEA Seattle/Tacoma Intl
3h 04mdirect
C$ 218Alaska Airlines
Mon, 11 Jan - Mon, 18 Jan
Alaska Airlines Logo
7:37 p.m. - 11:17 p.m.SEA  Seattle/Tacoma Intl-DEN Denver Intl
2h 40mdirect
Alaska Airlines Logo
7:54 p.m. - 9:59 p.m.DEN  Denver Intl-SEA Seattle/Tacoma Intl
3h 05mdirect
C$ 218Alaska Airlines
Thu, 8 Oct - Thu, 15 Oct
Delta Logo
8:00 p.m. - 11:55 p.m.SEA  Seattle/Tacoma Intl-DEN Denver Intl
2h 55mdirect
Delta Logo
6:00 a.m. - 8:10 a.m.DEN  Denver Intl-SEA Seattle/Tacoma Intl
3h 10mdirect
C$ 218Delta
Fri, 30 Oct - Tue, 3 Nov
Delta Logo
8:00 p.m. - 11:55 p.m.SEA  Seattle/Tacoma Intl-DEN Denver Intl
2h 55mdirect
Delta Logo
6:42 p.m. - 8:48 p.m.DEN  Denver Intl-SEA Seattle/Tacoma Intl
3h 06mdirect
C$ 218Delta
Thu, 29 Oct - Sun, 1 Nov
United Airlines Logo
7:04 p.m. - 10:45 p.m.SEA  Seattle/Tacoma Intl-DEN Denver Intl
2h 41mdirect
United Airlines Logo
7:40 a.m. - 9:47 a.m.DEN  Denver Intl-SEA Seattle/Tacoma Intl
3h 07mdirect
C$ 218United Airlines
Tue, 10 Nov - Sat, 14 Nov
Frontier Logo
8:09 p.m. - 9:45 a.m.SEA  Seattle/Tacoma Intl-DEN Denver Intl
12h 36m1 stop Los Angeles
Frontier Logo
1:04 p.m. - 3:12 p.m.DEN  Denver Intl-SEA Seattle/Tacoma Intl
3h 08mdirect
C$ 225Frontier
Booking Insights

Price, demand, and travel trends for Seattle to Denver flights

Use KAYAK data on prices, travel dates, airlines, and seasonal trends to compare options and book flights from Seattle to Denver with more confidence.

How much is a round-trip flight from Seattle to Denver?

Round-trip flights from Seattle to Denver start at C$ 192. Prices are below average for this route right now, with typical round-trip fares ranging from C$ 233 to C$ 469. The lowest price found in the past 5 days was C$ 192 on Frontier.

What's the cheapest day of the week to fly from Seattle to Denver?

Saturday is the cheapest day of the week to fly from Seattle to Denver and is 7% cheaper than the average day. Sunday is the most expensive day with flight prices 23% higher than average. Based on deals found by KAYAK users in the last 12 months.

What is the cheapest month to fly from Seattle to Denver?

  • January is the cheapest month to fly from Seattle to Denver at C$ 224 round-trip.
  • June (C$ 463) and July (C$ 428) are the most expensive months.
  • The price difference between flying in the cheapest and most expensive months is 106% on average.
This is based on KAYAK aggregated and averaged internal data over the past 12 months.

When are prices from Seattle to Denver the cheapest?

Flights from Seattle to Denver are cheapest 5 weeks before departure. Booking in this window typically costs about 45% less than the average last-minute fare (within 2 weeks of the flight), based on KAYAK data.

Expert advice

Expert advice for your flight from Seattle to Denver

 
KAYAK teamed up with top travel experts to share the best tips for your journey.
Our travel experts
Stefanie Waldek

Stefanie Waldek

Expert on United Airlines and Frontier

Stefanie Waldek is a freelance space, travel, and design writer based in Saratoga Springs, NY. Her words have appeared in Space.com, Travel + Leisure, Condé Nast Traveler, Architectural Digest, and House Beautiful, among other publications. An expert in aviation and expedition cruising, Stefanie is frequently up in the air or on the sea, likely en route to Antarctica or the Arctic.

Harriet Baskas

Harriet Baskas

Expert on Alaska Airlines

Harriet is an award-winning journalist who is happiest in an airport or an unusual museum. Her stories about airports, air travel, and the business of travel have appeared on NBC News, CNBC, USA TODAY, The Points Guy and other outlets. She is the creator of the StuckatTheAirport.com blog and the author of nine books. When not out on the road or exploring the latest airport amenities, she’s home in Seattle getting ready for the next adventure.

Key details for Seattle to Denver flights

Low season

February

Cheapest flight

C$ 110
Best time to beat the crowds (19% less expensive on average)
Most popular time to fly (33% more expensive on average)
Flights from Seattle to Denver

When to book flights from Seattle to Denver

Are your dates flexible? Find out the best times to travel from Seattle to Denver based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price

Flights from Seattle to Denver: the best tips from KAYAK users' own experiences

Insights shared by verified travellers who flew the route from Seattle to Denver 
DebraFlew with Alaska Airlines-Feb 2026
Seattle TSA much improved. Faster service. Baggage check-in ok. I'm sure will get faster as people get used to it.
Verified travelerFlew with Alaska Airlines-Mar 2025
Alaska Air is very efficient & on-time so allow enough time to get luggage, go thru Customs & Immigration, & long security lines. Terminals in SEA are readily accessible by trains but more signage is needed. Fortunately, Information booths are everywhere & are manned by very helpful staff.
MichaelFlew with Delta-Apr 2025
Train from Denver airport to downtown is easy to use.
Verified travelerFlew with Alaska Airlines-May 2024
When flying from Seattle to Denver, be ready to take our any electronics and put them in separate bins when going through security. You will also most likely have to take off your jacket as well. During our flight back the flight randomly changed so be on the lookout in case that happens to you! It was by chance that I checked my ticket and saw that the gate changed last minute.

Your Seattle to Denver flight questions, answered

Find helpful route details based on KAYAK data, including flight times, airports, airlines, and booking questions.

  • Is there anywhere to smoke at Seattle-Tacoma International Airport?

    While smoking is not allowed inside any of the terminals at Seattle-Tacoma International Airport, there are two locations outside where you may smoke. The first is near the north end of the baggage claim level, and the second is across from the small parking lot. To determine if you are allowed to smoke, look for ashtrays and double check that there are no airport signs prohibiting it.

  • What is there to do while waiting at Seattle-Tacoma International Airport?

    In addition to periodic live music performances, Seattle-Tacoma International Airport also has a diverse Art Walk that is 0.5 mi long and begins near Gate A 14. There are also several Digiboo self-service kiosks located throughout the airport that allow travelers to download movies and televisions shows directly onto their portable devices.

  • Are there any amenities for pets at Denver International Airport?

    There are several pet relief zones located in the centers of Terminals A, B, and C at Denver International Airport and they provide pet owners with waste disposal bags, trashcans, and running water. Additionally, there is a Paradise 4 Paws Pet Resort adjacent to the main terminal that offers both pet boarding and grooming services.

  • Where can I grab a meal at Denver International Airport?

    Boulder Beer Tap House is located in the Jeppesen Terminal of Denver International Airport and serves a selection of burgers, appetizers, and salads, while Cantina Grill is located nearby and has a Mexican-inspired menu. The Denver Chophouse is located near the A Gates and is known for its vegan and gluten-free meals.

  • Which airlines offer extra legroom and free seat selection on Seattle to Denver flights?

    Among airlines operating Seattle to Denver 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.

  • Which airlines are available on the route from Seattle to Denver?

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

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

  • Which airports can I use when flying from Seattle to Denver?

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

  • Which airlines include bags at no extra cost on Seattle to Denver flights?

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

    • Frontier: a carry-on bag and a checked bag in Economy Class
    • Alaska Airlines: a carry-on bag and a checked bag in Economy Class
    • United Airlines: a carry-on 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.

  • Which cabin classes can I book on flights from Seattle to Denver?

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

  • How much can I save by taking a layover when flying from Seattle to Denver?

    On this route, layover flights are cheaper than direct options on average. Layover fares average C$ 277 round-trip via Ontario (ONT), compared to C$ 348 for direct.

  • What is the standard checked bag allowance on flights from Seattle to Denver?

    There is no standard. Checked bag policies vary by airline on this route. Most carriers charge C$ 49–C$ 139 for the first checked bag in economy. Premium fares and elite status bookings typically include a free checked bag.

  • Which aircraft model is used most often on flights from Seattle to Denver?

    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 737-800 Passenger/BBJ2 (winglets) variants.

  • Which airports do connecting flights from Seattle to Denver pass through?

    Connecting flights from Seattle to Denver most commonly pass through:

    • Ontario (ONT) – 58% of one-stop connections
    • Salt Lake City (SLC) – 42% of one-stop connections
    Together, these airports account for 100% of one-stop bookings on this route.

  • Can I save money by using flexible dates for flights from Seattle to Denver?

    On the Seattle to Denver route, being flexible with your departure day can save you up to 25%. Saturday is the cheapest day at C$ 325 round-trip on average, while Sunday is the most expensive at C$ 429 – a C$ 104 difference. Cheaper weekend fares like these are typical of routes dominated by weekday business travel.

  • At what point is a flight considered delayed on the route from Seattle to Denver?

    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 Seattle to Denver route, 15% of flights were delayed in the past 3 months, with delays averaging 2 hours 23 minutes.

  • How are flight departures from Seattle to Denver spread across the day?

    Morning is the busiest departure period on Seattle to Denver flights, with 44% leaving in that window. Afternoon departures account for 38%, Evening flights for 18%, and Night flights for 0%.

  • Which popular places can I visit in Denver?

    Some of the most popular sights in Denver are Colorado Convention Center, 16th Street Mall, and Sheraton Denver Downtown Hotel. These are among the most viewed places in Denver on KAYAK.

  • What are the earliest and latest flights from Seattle to Denver?

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

    • Earliest: departs at 5:00 am and lands at 7:46 am
    • Latest: departs at 10:00 pm and lands at 12:46 am.

    The flight takes about 2h 46m.

  • How expensive are last-minute Seattle to Denver flights?

    Last-minute fares on this route – booked within 2 weeks of departure – run 37% above the route average of C$ 347. Book 5 weeks before departure for the lowest fares.

  • How long does a flight from Seattle to Denver take?

    A direct flight from Seattle to Denver takes 2h 46m, covering 2,646 km.

  • Do I need a passport to fly from Seattle to Denver?

    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.

  • Have flight prices from Seattle to Denver changed much recently?

    Yes. Based on fares seen in the past 5 days, round-trip prices on this route showed a wide range, from about C$ 192 to C$ 1,356. That means the highest observed fare was about 7x higher than the lowest one.

  • How are flight prices from Seattle to Denver looking right now?

    One-way fares from Seattle to Denver are currently lower than usual. Average one-way flight prices are about C$ 114, which is 54% below the typical average for this route.

  • How does United Airlines's on-time performance compare to other airlines on Seattle to Denver flights?

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

    • United Airlines: 92% on time
    • Frontier: 87% on time
    • Alaska Airlines: 85% on time

    On average, flights on this route are punctual 85% of the time.

  • How do delay rates compare for morning and evening flights from Seattle to Denver?

    Night 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.

  • How much time can I save by choosing a different layover airport when travelling from Seattle to Denver?

    Flying via Salt Lake City (SLC) gives the shortest average 1-stop total travel time at 7h 38m, compared with 8h 36m via Ontario (ONT).

  • What is the time difference between Seattle and Denver?

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

  • What car rental options are available at Denver Intl Airport (DEN)?

    Denver Intl Airport (DEN) hosts 5 major car rental companies, with daily rates starting from around C$ 22 for economy cars. Top options include:
    • Routes Car & Truck Rentals
    • Ace
    • NU Car
    • Europcar
    • Hertz

  • How much should I expect to pay for a Seattle to Denver flight?

    Round-trip flights from Seattle to Denver range from C$ 233 to C$ 469, with an average of C$ 347 over the past 12 months. Anything below C$ 233 counts as a good deal.

  • Which airlines offer Wi-Fi on Seattle to Denver flights?

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

    • • Alaska Airlines
    • • Delta
    • • JetBlue

    Pricing varies by airline and fare class. Some plans are included with the ticket or loyalty program; others are paid add-ons priced by flight length.

Your guide to booking Seattle to Denver flights

Get tips on when to book, when to fly, and what to know before your trip.
  • If your dates are flexible, aim for a Saturday departure instead of Sunday. On this route, Saturday flights average C$ 325 – about C$ 104 less than Sunday (24% savings) based on the last 12 months.
  • For the best chance at a low fare, aim to book around 5 weeks before you fly. On this route, that window historically saves about 45% versus last-minute pricing (KAYAK booking data, last 12 months).
  • If you can choose when to travel, plan your Seattle to Denver trip for January. Fares historically average C$ 224 round-trip in that month – typically C$ 239 less than the most expensive month, which is June (based on the last 12 months).
  • If arriving on time is high on your priority list, United Airlines is the strongest pick on this route. 92% of United Airlines flights from Seattle to Denver arrived on time in the past 3 months, slightly above the route's average on-time arrival rate of 85%. When flights on this route do arrive late, the average delay is 2 hours23 minutes, so choosing a carrier with strong on-time performance can make a difference on tight schedules.
  • If you have the time, taking a 1-stop flight through Ontario Airport (ONT) can be cheaper than flying direct. The cheapest layover option averages C$ 277 round-trip on this route – about C$ 71 less than direct flights (based on the last 12 months).
  • If you're arriving late at night and need somewhere to stay, check out these hotels close to Denver Intl Airport.
    - The Westin Denver International Airport
  • For travelers looking for non-stop flights from Seattle to Denver, book your reservation with either United, Delta, or Frontier Airlines, as each of these companies offers many flights without layovers. If you would like some extra perks, look into flying with Southwest Airlines, as they provide free checked baggage and snacks.
  • If you’re trying to find a way to pass the time before boarding your flight from Seattle to Denver, purchase an entry ticket for the Club at SEA in Seattle-Tacoma International Airport (SEA). This lounge is open to customers of all airlines and provides guests with snacks, magazines, televisions, and games.
  • Have a question about the airport or need help finding a specific service? Look for the Airport Volunteers stationed throughout Seattle-Tacoma International Airport in bright blue jackets. These volunteers can help you find your gate, recommend dining options, and tell you about the airport’s various amenities.
  • If you are feeling sore after being cooped up in a plane for several hours, consider getting a quick massage at A Massage in Denver International Airport (DEN). With two locations near the A and B Gates, this massage parlor is a quick and convenient way to let go of any tension and stress.
  • For those that are traveling with a small child, take note of the fact that there are private nursing rooms located in each terminal of Denver International Airport. These rooms contain seating, outlets, changing tables, and sinks, and they are free to access.

Prefer to fly direct from Seattle to Denver?

 
Find which airlines fly direct from Seattle/Tacoma Intl Airport to Denver Intl Airport, which days they fly and book direct flights.

Direct departures

Seattle/Tacoma Intl to Denver Intl

Monday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Tuesday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Wednesday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Thursday

Alaska Airlines,American Airlines,Delta, +3 more

Alaska Airlines,American Airlines, +4 more

Friday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Saturday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Sunday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

See more nonstop flights

Direct returns

Denver Intl to Seattle/Tacoma Intl

Monday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Tuesday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Wednesday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Thursday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Friday

Alaska Airlines,American Airlines,Delta, +3 more

Alaska Airlines,American Airlines, +4 more

Saturday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Sunday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

See more nonstop flights

More options for your flight from Seattle to Denver

Complete your trip to Denver with a hotel stay or car rental