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$111+ Cheap flights from Colorado to Seattle (SEA)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 8/11. Fares are subject to change and may not be available on all flights or dates of travel.
DEN — SEA
Jul 16 — Jul 231
Thu 7/16
Thu 7/23
1 adult, Economy
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Cheap flight deals from Colorado to Seattle

Cheapest flights from Colorado to Seattle
Explore the most affordable flight options available from Colorado to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on June 16, 2026.

This Cheapflightsfares deal was found by Cheapflights users on 6/14. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/87:45 am
DEN
-
SEA
Nonstop3h 03m
Frontier
Wed 9/167:00 am
SEA
-
DEN
Nonstop2h 51m
Frontier
Deal found 6/14$170
This Frontier deal was found by Cheapflights users on 6/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/67:00 am
DEN
-
SEA
Nonstop3h 04m
Frontier
Wed 8/267:41 pm
SEA
-
DEN
Nonstop2h 55m
Frontier
Deal found 6/11$171
This Frontier deal was found by Cheapflights users on 6/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/57:45 am
DEN
-
SEA
Nonstop3h 03m
Frontier
Wed 9/167:00 am
SEA
-
DEN
Nonstop2h 51m
Frontier
Deal found 6/15$172
This Trip.com deal was found by Cheapflights users on 6/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/257:45 am
DEN
-
SEA
Nonstop3h 06m
Frontier
Thu 10/17:00 am
SEA
-
DEN
Nonstop2h 51m
Frontier
Deal found 6/11$173
This Kiwi.com deal was found by Cheapflights users on 6/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/167:00 am
DEN
-
SEA
Nonstop3h 04m
Frontier
Wed 8/197:41 pm
SEA
-
DEN
Nonstop2h 55m
Frontier
Deal found 6/12$174
This Cheapflightsfares deal was found by Cheapflights users on 6/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/1010:29 pm
DEN
-
SEA
Nonstop2h 58m
Frontier
Sun 9/137:41 pm
SEA
-
DEN
Nonstop2h 53m
Frontier
Deal found 6/15$175
This Super.com deal was found by Cheapflights users on 6/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/187:45 am
DEN
-
SEA
Nonstop3h 03m
Frontier
Fri 8/213:19 pm
SEA
-
DEN
Nonstop2h 48m
Frontier
Deal found 6/15$176
This Frontier deal was found by Cheapflights users on 6/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/110:29 pm
DEN
-
SEA
Nonstop2h 58m
Frontier
Mon 10/57:41 pm
SEA
-
DEN
Nonstop2h 53m
Frontier
Deal found 6/15$177
This Frontier deal was found by Cheapflights users on 6/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/207:45 am
DEN
-
SEA
Nonstop3h 06m
Frontier
Fri 10/237:41 pm
SEA
-
DEN
Nonstop2h 53m
Frontier
Deal found 6/12$178
This Cheapflightsfares deal was found by Cheapflights users on 6/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/312:00 pm
DEN
-
SEA
Nonstop3h 04m
Frontier
Sun 9/67:41 pm
SEA
-
DEN
Nonstop2h 55m
Frontier
Deal found 6/12$179
This Frontier deal was found by Cheapflights users on 6/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/277:45 am
DEN
-
SEA
Nonstop3h 06m
Frontier
Sat 10/317:41 pm
SEA
-
DEN
Nonstop2h 53m
Frontier
Deal found 6/12$180
This Cheapflightsfares deal was found by Cheapflights users on 6/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/27:13 am
DEN
-
SEA
Nonstop3h 04m
Frontier
Sat 8/157:06 pm
SEA
-
DEN
Nonstop2h 52m
Frontier
Deal found 6/11$181

Find flight deals from Colorado to Seattle

Keep the following information in mind while searching for Colorado to Seattle flight deals. Data was last updated June 16, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$170
(Cheapflightsfares)

One-way from

$111
(Frontier)

Popular in

June

Cheapest in

January

Average price

$305

Good round-trip deal

$293 or less

Good one-way deal

$170 or less
Provider with most accurate pricing for Denver Intl-Seattle/Tacoma Intl flight deals.
Search Deals
Provider most trusted by Cheapflights users for Denver Intl-Seattle/Tacoma Intl flights.
Search Deals
From Colorado to Seattle/Tacoma Intl
Search Deals
One-way flight from Colorado to Seattle/Tacoma Intl
Search Deals
Highest demand for flights based on searches. 21% potential increase in price ($62 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($8 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in June 2026
Search Deals
Price to beat on a round-trip flight from Colorado to Seattle/Tacoma Intl.
Search Deals
Price to beat on a one-way flight from Colorado to Seattle/Tacoma Intl.
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Colorado to Seattle that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated June 16, 2026.
Use the filters below to find and compare flights from Colorado to Seattle that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

Colorado SpringsSeattle

COS - SEA

COSSEA

Colorado Springs

Sat 9/12

8:00 am-4:55 pm

2 stops9h 55m

Seattle/Tacoma Intl

Wed 9/23

12:36 pm-10:54 pm

2 stops9h 18m

$245

Grand JunctionSeattle

GJT - SEA

GJTSEA

Grand Junction Regnl

Tue 7/21

7:34 am-4:40 pm

2 stops10h 06m

Seattle/Tacoma Intl

Wed 7/29

11:09 am-6:17 pm

1 stop6h 08m

$276

HaydenSeattle

HDN - SEA

HDNSEA

Hayden Yampa Valley

Sat 10/24

1:43 pm-5:37 pm

1 stop4h 54m

Seattle/Tacoma Intl

Wed 10/28

5:07 am-12:35 pm

1 stop6h 28m

$295

Grand JunctionSeattle

GJT - SEA

GJTSEA

Grand Junction Regnl

Wed 7/29

6:56 pm-11:59 pm

1 stop6h 03m

Seattle/Tacoma Intl

Tue 8/18

12:36 pm-9:56 pm

2 stops8h 20m

$300

Colorado SpringsSeattle

COS - SEA

COSSEA

Colorado Springs

Sat 9/19

7:00 am-4:04 pm

2 stops10h 04m

Seattle/Tacoma Intl

Wed 9/23

5:00 am-1:17 pm

1 stop7h 17m

$302

Colorado SpringsSeattle

COS - SEA

COSSEA

Colorado Springs

Tue 8/25

8:38 am-8:43 pm

2 stops13h 05m

Seattle/Tacoma Intl

Wed 8/26

5:00 am-10:44 am

1 stop4h 44m

$302
Quickest round-trip

DenverSeattle

DEN - SEA

DENSEA

Denver Intl

Sat 8/22

9:15 am-1:40 pm

1 stop5h 25m

Seattle/Tacoma Intl

Sat 8/29

5:40 pm-9:25 pm

Nonstop2h 45m

$311

HaydenSeattle

HDN - SEA

HDNSEA

Hayden Yampa Valley

Tue 9/1

7:05 am-11:44 am

1 stop5h 39m

Seattle/Tacoma Intl

Wed 9/2

2:34 pm-8:24 pm

1 stop4h 50m

$317

DenverSeattle

DEN - SEA

DENSEA

Denver Intl

Wed 8/26

6:17 am-12:39 pm

1 stop7h 22m

Seattle/Tacoma Intl

Sat 8/29

10:18 am-7:26 pm

1 stop8h 08m

$325

DenverSeattle

DEN - SEA

DENSEA

Denver Intl

Tue 8/18

6:00 am-1:13 pm

1 stop8h 13m

Seattle/Tacoma Intl

Wed 8/19

10:18 am-7:26 pm

1 stop8h 08m

$325

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/11

Showing 1-10 of 60 resultsSorted by cheapest first
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Best time to book a flight from Colorado to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from Colorado with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Colorado to Seattle

What is the cheapest month to book a flight from Colorado to Seattle?

Currently, January is the cheapest month in which you can book a flight from Colorado to Seattle (average of $30). Flying from Colorado to Seattle in December is currently the most expensive (average of $454). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from CO to SEA?

Find hourly flight availability from Colorado to Seattle. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated June 16, 2026.

Unlike in the morning, when flights are generally more expensive, you can save up to 48% on flights from Colorado to Seattle by exploring options for tickets in the evening.

Weekly flight availability from Colorado to Seattle

Explore weekly flight availability from Colorado to Seattle. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated June 16, 2026.

The most flights from USCO to SEA are scheduled on a Monday (50 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (32 on average).

How much does it cost to fly round-trip from Colorado to Seattle?

How far ahead should I book a flight from Colorado to Seattle?

The price you pay for your flight from Colorado to Seattle may vary depending on when you book. For the best chance of a lower fare, look to book 26 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

What is the cheapest day to fly from Colorado to Seattle?

Use this chart to determine the cheapest time to fly round-trip from Colorado to Seattle. Price data was last updated on June 13, 2026.

Travelers seeking maximum savings on their Colorado to Seattle flight should consider departing on Tuesday afternoons when fares are most often at their lowest. Monday evenings flights should be avoided if possible as fares are typically the most expensive at this time.

Related info for your journey

Find useful and relevant information for your journey from Colorado to Seattle. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to Seattle from Colorado?

    Seattle/Tacoma Intl (SEA) is the airport you will fly into if you book a flight from Colorado to Seattle. It is only a 11.4 mi journey from Seattle/Tacoma Intl (SEA) to Seattle’s city center.

  • How popular is this Colorado to Seattle flight route?

    This flight path from Colorado to Seattle/Tacoma Intl was viewed by 122 users in the past month. Keep an eye out for changes in search interest prior to high and low season.

  • How long is the flight from Colorado to Seattle?

    There are many flights that can get you from Colorado to Seattle in 4h 54m. Fly via Delta, United Airlines, or Southwest to get the fastest option. The distance from Colorado to Seattle is about 889 mi. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

  • What are the cheapest airlines to fly from Colorado to Seattle one-way?

    To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $32. Southwest flights start at $63 while deals on Delta start at $68 one-way.

  • What are the most popular routes from Colorado to Seattle?

    Most travelers choose Denver Intl - Seattle/Tacoma Intl, Colorado Springs - Seattle/Tacoma Intl or Grand Junction Regnl - Seattle/Tacoma Intl when deciding on the best route from Colorado to Seattle.

  • What are the most reliable airlines from Colorado to Seattle?

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Colorado to Seattle on time: Korean Air (99%), Japan Airlines (91%), WestJet (90%).

  • What are the cheapest flights from Colorado to Seattle?

    While on average a flight from Colorado to Seattle is generally $723, our data shows the cheapest flight currently is $128. When looking at the most popular route, (Denver Intl - Seattle/Tacoma Intl), you can expect to pay $150 for that flight.

  • Can I find deals for flights from Colorado to Seattle that include hotel bookings?

    Yes. In addition to deals on Colorado to Seattle flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Colorado to Seattle?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Colorado to Seattle.

  • Can I find deals for business class flights from Colorado to Seattle?

    Yes. Cheapflights offers flight deals from Colorado to Seattle by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Colorado to Seattle?

    Currently, January is the cheapest month in which you can book a flight from Colorado to Seattle (average of $30). Flying from Colorado to Seattle in December is currently the most expensive (average of $454). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
SeaTac
Tacoma
Lacey
Ocean Shores
Leavenworth
Olympia
Edmonds
Snoqualmie
Tumwater
Tukwila
Puyallup
Kent
Lynnwood
Renton
Ellensburg
Fife
Lakewood
Issaquah
Shoreline
Marysville

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Colorado to Seattle

See prices for flight routes from nearby airports that may be better suited for you.
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Top 7 airlines flying from Colorado to Seattle

Discover the top 7 airlines that operate flights from Colorado to Seattle. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated June 16, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$55Average$183FlexibilityNo cancel feeOn-time62%
DeltaCheapest$82Average$291FlexibilityNo cancel feeOn-timeN/A
Hawaiian AirlinesCheapest$88Average$220FlexibilityNo cancel feeOn-time85%
United AirlinesCheapest$116Average$416FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$117Average$337FlexibilityNo cancel feeOn-time63%
Alaska AirlinesCheapest$126Average$364FlexibilityNo cancel feeOn-time75%
American AirlinesCheapest$244Average$451FlexibilityNo cancel feeOn-time71%

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