Cheapest return flights from Seattle to Denver in December from $100

AirHint found the following cheapest return flights from Seattle (SEA) to Denver (DEN) in December 2025 (see full year).

Return flights

05 Dec - 07 Dec Frontier Airlines direct
11 Dec - 14 Dec Frontier Airlines direct
12 Dec - 15 Dec Alaska Airlines direct
10 Dec - 16 Dec Alaska Airlines direct
10 Dec - 14 Dec Alaska Airlines direct
23 Dec - 02 Jan Frontier Airlines direct
22 Dec - 27 Dec Frontier Airlines direct
04 Dec - 09 Dec Frontier Airlines
04 Dec - 09 Dec Southwest Airlines direct
20 Dec - 25 Dec Frontier Airlines direct
24 Dec - 28 Dec Frontier Airlines direct

Also check the deals for one-way flights from Seattle to Denver in December.

Skyscanner

The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.

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