Average price (all airlines)
There are 11 flights available on United Airlines from Seattle to Denver for under $300. These prices can change based on many factors including date and time. To find SEA-DEN flight prices for your dates, click here.
When planning your SEA-DEN trip, keep in mind that United Airlines is typically rated 5.8/10. This rating comes from 762 reviews by Cheapflights users who have traveled with United Airlines.