Colorado's 1st district is 100% urban, containing the entirety of Denver as well as a few of its suburbs. The district is majority White (59.43%), followed by Hispanic (27.64%), Black (8.65%), and Asian (3.53%).

The Democratic candidate and incumbent in the district is Diana DeGette, who has served as the district's representative since 1997 and has won with at least 65% of the vote in every election since 1998. The Republican candidate is Casper Stockham, who also sought election to the House of Representatives in 2016, losing to DeGette by 40 percentage points.

The district votes reliably democratically, giving the democratic candidate at least 60% of the vote in each of the last 5 presidential elections. DeGette won election in 2014 by over 35 points, and the district voted in favor of Hillary Clinton over Trump by 45 percentage points.