Frontier offers extra comfort seats with 32” separation for a fee, ideal for taller passengers.
Frontier’s Board First option is available with a carry-on purchase or for elite members.

Most accurate provider | CheapOair 3 stars |
|---|---|
Most trusted provider | CheapOair 3 stars |
Round-trip from | $58 (Cheapflightsfares) |
One-way from | $54 (Expedia) |
Popular in | June |
Cheapest in | January |
Average price | $155 |
Good round-trip deal | $210 or less |
Good one-way deal | $140 or less |
Fly from
Fly to
Route
Depart
Return
Price
DenverSeattle
DEN - SEA
DENSEA
Denver Intl
Wed 3/11
6:16 pm-8:26 pm
Nonstop3h 10m
Seattle/Tacoma Intl
Mon 3/16
3:16 pm-6:56 pm
Nonstop2h 40m
DenverSeattle
DEN - SEA
DENSEA
Denver Intl
Wed 2/25
7:45 am-9:49 am
Nonstop3h 04m
Seattle/Tacoma Intl
Sat 2/28
5:00 am-8:38 am
Nonstop2h 38m
DenverSeattle
DEN - SEA
DENSEA
Denver Intl
Wed 2/25
7:00 am-9:10 am
Nonstop3h 10m
Seattle/Tacoma Intl
Sat 2/28
3:16 pm-6:56 pm
Nonstop2h 40m
DenverSeattle
DEN - SEA
DENSEA
Denver Intl
Thu 2/5
11:49 am-6:43 pm
1 stop7h 54m
Seattle/Tacoma Intl
Mon 2/9
7:54 pm-11:35 pm
Nonstop2h 41m
DenverSeattle
DEN - SEA
DENSEA
Denver Intl
Fri 3/6
11:38 am-4:57 pm
1 stop6h 19m
Seattle/Tacoma Intl
Sat 3/7
8:14 pm-11:59 pm
Nonstop2h 45m
DenverSeattle
DEN - SEA
DENSEA
Denver Intl
Wed 2/11
1:10 pm-8:20 pm
1 stop8h 10m
Seattle/Tacoma Intl
Wed 2/18
6:25 am-1:35 pm
1 stop6h 10m
DenverSeattle
DEN - SEA
DENSEA
Denver Intl
Thu 2/5
7:00 am-9:11 am
Nonstop3h 11m
Seattle/Tacoma Intl
Tue 2/10
2:36 pm-11:58 pm
1 stop8h 22m
DenverSeattle
DEN - SEA
DENSEA
Denver Intl
Sat 2/28
8:00 am-10:15 am
Nonstop3h 15m
Seattle/Tacoma Intl
Sun 3/1
6:15 am-3:45 pm
1 stop8h 30m
DenverSeattle
DEN - SEA
DENSEA
Denver Intl
Fri 2/27
3:40 pm-11:25 pm
1 stop8h 45m
Seattle/Tacoma Intl
Sun 3/1
5:50 am-12:25 pm
1 stop5h 35m
DenverSeattle
DEN - SEA
DENSEA
Denver Intl
Wed 3/18
7:25 am-2:03 pm
1 stop7h 38m
Seattle/Tacoma Intl
Tue 3/24
3:50 pm-11:44 pm
1 stop6h 54m
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy2 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*1 star | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*2 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy- | Trust Score*1 star | |
| Price Accuracy- | Trust Score*1 star | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars |
To ensure you get the cheapest price possible for a flight from Denver to Seattle, you should look to book at least 39 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.
Currently, February is the cheapest month in which you can book a flight from Denver to Seattle (average of $48). Flying from Denver to Seattle in July is currently the most expensive (average of $118). 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.
When flying from Denver to Seattle, the time of day you fly usually plays a role in the price. Save by searching for a flight in the evening, which can drop the price by up to 28% versus a flight in the morning.
Travelers seeking maximum savings on their Denver to Seattle flight should consider departing on Friday evenings when fares are most often at their lowest. Monday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
About 19% of weekly flights between Denver and Seattle have experienced delays in the past year, with the average delay time being 145 minutes.
Historically, flights departing in the morning are less likely to be delayed, whereas flights leaving at night tend to experience delays more often.
Wednesday tends to have the lowest number of delays on this route, whereas Sunday has historically faced a higher average of delays compared to other days of the week.
Over the last year, Delta have had the lowest number of delays on this route, with just 13% of flights being delayed.
Boarding
Crew
Overall
Food
Entertainment
Comfort
Reviews
Anonymous,Dec 2025
SJC - SEA
Boarding
Crew
Overall
Food
Entertainment
Comfort
Reviews
Anonymous,Dec 2025
SJC - SEA
Boarding
Crew
Overall
Food
Entertainment
Comfort
Reviews
Anonymous,Dec 2025
SJC - SEA
Boarding
Crew
Overall
Food
Entertainment
Comfort
Reviews
Anonymous,Dec 2025
SJC - SEA
Boarding
Crew
Overall
Food
Entertainment
Comfort
Reviews
Anonymous,Dec 2025
SJC - SEA
Boarding
Crew
Overall
Food
Entertainment
Comfort
Reviews
Anonymous,Dec 2025
SJC - SEA
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$54 | Average$162 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$98 | Average$227 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$108 | Average$231 | FlexibilityNo cancel fee | On-time85% | |
| Cheapest$117 | Average$241 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$121 | Average$293 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$134 | Average$271 | FlexibilityNo cancel fee | On-time75% |