Frontier's Economy Bundle includes a carry-on and seat choice, ideal for budget travelers.
Opt for Premium Bundle for priority boarding and extra legroom, just $20 more than Economy.
Planning a trip from Seattle to Denver? KAYAK’s data-powered insights will help you find cheap flights. Learn the best time to fly, how early to book your ticket, and other tips to secure great prices.
The most affordable time to fly from Seattle to Denver is typically on a Tuesday or Wednesday, with January being the cheapest month overall.
Booking Advance: Purchase tickets at least 15 days in advance for the best rates.
Cheapest Airline: Frontier Airlines generally offers the lowest fares on this route.
Direct Flights: Direct flights, particularly with Frontier, are usually cheaper than those with layovers.
Route Selection: The route from Seattle/Tacoma Intl to Denver Intl is the most cost-effective option.
This feature is powered by ChatGPT: an OpenAI-developed artificial intelligence model trained with KAYAK proprietary data and third-party data not verified by KAYAK.
Low season | January |
---|---|
High season | May |
Cheapest flight | $73 |
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
ANA, Air Tahiti Nui, Alaska Airlines, +18 more
ANA, Air Tahiti Nui, +19 more
17
18
Tuesday
Air France, Air Tahiti Nui, Alaska Airlines, +16 more
Air France, Air Tahiti Nui, +17 more
15
16
Wednesday
ANA, Air France, Air Tahiti Nui, +19 more
ANA, Air France, +20 more
18
19
Thursday
ANA, Air France, Air Tahiti Nui, +18 more
ANA, Air France, +19 more
17
18
Friday
ANA, Air Tahiti Nui, Alaska Airlines, +18 more
ANA, Air Tahiti Nui, +19 more
17
18
Saturday
Air France, Air Tahiti Nui, Alaska Airlines, +19 more
Air France, Air Tahiti Nui, +20 more
18
19
Sunday
ANA, Air France, Air Tahiti Nui, +20 more
ANA, Air France, +21 more
19
20
Direct returns
Denver Intl to Seattle/Tacoma Intl
Monday
ANA, Air France, Air Tahiti Nui, +18 more
ANA, Air France, +19 more
17
18
Tuesday
ANA, Air France, Air Tahiti Nui, +15 more
ANA, Air France, +16 more
14
15
Wednesday
ANA, Air France, Air Tahiti Nui, +18 more
ANA, Air France, +19 more
17
18
Thursday
ANA, Air France, Air Tahiti Nui, +17 more
ANA, Air France, +18 more
16
17
Friday
ANA, Air France, Air Tahiti Nui, +18 more
ANA, Air France, +19 more
17
18
Saturday
ANA, Air France, Air Tahiti Nui, +18 more
ANA, Air France, +19 more
17
18
Sunday
ANA, Air France, Air Tahiti Nui, +19 more
ANA, Air France, +20 more
18
19
Great experience flying Southwest. The crew was really kind and helpful, and very friendly with our toddler.
Great experience flying Southwest. The crew was really kind and helpful, and very friendly with our toddler.
Very good. Sad to learn Southwest is going start to charge for bags
Our flight was diverted from being a non-stop to getting within 150 miles and requiring another plane. We heard 4 or 5 different versions from SW as to why we had to stop, then wait for a replacement plane. Five hour delay, weather did not come up as a single excuse.... communication was not clear and well explained. No one really took charge!
My flight to Chicago left and landed early. My return flight left two minutes late and arrived 2 minutes late. My seat selections were ideal! There were no snacks going to Chicago and no snacks on the return trip. There are no charging outlets on board.
WiFi on the flight was not working. Thus, entertainment options were limited.
Great flight staff. Ease of boarding. Overall, very uneventful and easy trip.
Plane late from DC to Austin 30 minutes. Crew made up much of the time enroute to San Diego.
I really like open seating. I hate that I've heard this is going away. This is one of the unique things that makes Southwest my goto choice.
For the first time in a long time we had a flawless experience with Southwest. Both flights were early and no mechanical errors at all. We were shocked and pleasantly surprised 😮.
One of the crew performed a hilarious skit to accompany the standard instructions. Passengers enjoyed it so much they applauded at the end!
No food, just a snack on a Seattle to Boston flight? VERY chintzy.
Behind schedule. Lots of time on tarmac. Perhaps unavoidable. Better than crashing!!
It's a pity we missed our flight by 2 minutes.
Did not travel - unexpected medical emergency. Nonrefundable tickets, but Alaska Air sent credit vouchers for the entire amount (very generous, and I didn't expect that). However, I paid for insurance with Kayak's partner company. The 'insurance' might pay for lost baggage, but they referred to the contract in refusing to a dime on the policy. (If you died from a heart attack in the waiting area, I suspect they would claim the right to DENY if your general practitioner had found high blood pressure previously and prescribed daily HTCZ pills - even tiny ones.) They described a policy to deny any claim with even the slightest whiff of pre-existing. I suspect that they probably almost NEVER pay money out on a medical claim, and that their 'local medical assistance' has no coverage either - that it's just an abusive profit center sending gigantic bills while contributing nothing from your 'policy coverage'.
Not good. Didn’t get to our final destination. No reimburseme t for lost time
It was fine. Very friendly crew. Smooth flight. Landing was a little rough though.
Start to finish perfect flight. I'll be traveling from Cleveland to Seattle more often, And I believe you're going to be my go to
Delayed had to stand for hours guy beside me was to big for his seat and crowded me I paid for upgrade to be stuck there Not much beverage or food service
Short flight so little time for any beverages or snacks-there was no entertainment on this flight
I am shocked at how utterly mediocre the First Class experience was on Alaska Airlines- I really expected better. There was a delay with the food delivery, so we sat on the plane for an extra 30 minutes- not once during that time was I, nor anyone else in First Class offered anything at all, not even water. There's no tv or entertainment available? Really? In modern day? And the Wifi was $8 for the connection that actually works, but free for the connection that didn't work at all? What century is this? While friendly, the staff seemed to be much more concerned with their own personal time while working- listening to headphones, on their phones until someone needed them, I'm so disappointed I can't even believe I was able to find these words.
Flights on time. .Ride was as comfortable as can be expected in steerage. Luggage arrived at destination. Attendants were fairly friendly.
Great staff. Wifi is terrible. Signing up for skylines is a painstaking process. Had to call customer service just to get my flight itinerary and confirmation sent to me. Consistent delays. A well staffed company that is run so poorly. Upper management needs to be renewed.
The WiFi didn't seem as fast as it normally is
Thank you for not flipping the plane on the run way. You guys get a 5 star rating for the flight!!!
The crew was wonderful and attentive. The seats near exit row were restrictive. Offer healthy snacks please
Delta is a premier airline so my expectations are most always met.
Seats are much much more comfortable than United, which is what I usually fly
Zero updates from the pilots for 30 minutes in the tarmac
Boarding is, as it always is… horrible. Gate lice. Slow moving zones. Too many people with carry ons
I loved having a most black flight crew during Black History Month; rather by design or accident I appreciated the representation. ❤️
Food choices were very limited. Taste of the dishes was average.
I liked all the informational texts. I always knew where to go and when .
Received an email the night before showing that there would be seatback entertainment on our flight. We get on and there was no seatback entertainment. And then it was a scramble to try to set up the iPads for the kids before takeoff so they could watch something for the four hour flight.
The reason I don’t fly United. No in seat entertainment for a long flight and inconsistent WiFi and entertainment available from my device.
It was a good flight. Nothing comes to mind about how it could have been better. It was a newer plane, seemed like a great upgrade from your older ones. Staff was very good as well.
The food for long haul was poor compared to Singapore airlines economy. Pasta plain with tomato sauce . Singapore airlines give me Hagen dash small ice cream cup it was great. The choices of dinner course Singapore air also much better The crew mostly friendly. The economy seat are as expected.
The plane was clean. The staff was excellent. The flight attendants were very good. Enjoyable flight. Overall. The seats in the back are too small but, will always be.
Flight was 3 1/2 hour delayed with no credit or meal vouchers
late departure due to some unspecified issue with ventilating the cabin. They got it running but it was FREEZING for the whole flight. I asked for a blanket but they didn't provide one. They could not turn up the heat. it was quite miserable.
Liked that we left on time for each flight. Snacks not the best, but we're okay.
The plane failed preflight inspection, so we sat there for 90 mins while they tried to fix it. Ultimately, everything was remedied and we made our connecting flight; instead of a 2 hour layover at the airport, we spent it waiting on the plane.
I loked walking out on the tarmac to board and no first class. I didn't like that they have no snacks or onboard wifi to bide your time.
The seats were extremely hard and uncomfortable. It was disappointing even for a budget airline.
Delayed each time on a round trip with no significant weather interference. Updates to flight times came after the fact. 30 min behind in boarding and board and phone still show an on time departure. Some mysterious extra 300 miles that came so surprising they had to fuel while we were already on board?
Our flight was canceled for no known reason. We weren’t told until we were checking in at 5:00 am. This was after our last flight with Frontier where we sat on the plane for three hours (not an exaggeration) before we took off because of a mechanical issue. We won’t be flying Frontier again.
Allowed me to chose my seat without extra charge (I purchased full-price ticket) and boarding was in group1. Didn't even serve water.
Stuck in Phoenix for two days, not even a hotel voucher offered.
Every day about it was very different all the boarding pass where all wrong l miss flight no refund all crazy
Flight got delayed for 3.5 hours, and for the first hour after the departure time there was no update from the gate folks...
Both flights were delayed. The sizing of bags is crazy. I know it is advertised as a no frills cheaper option but it does feel like you are being extorted for money the whole way-- $20 dollars to talk to a gate agent? Charging for soda a pretzels? I don't think I will be flying Frontier again if I can help it. That said, all the staff were wonderful.
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