Colorado's 2nd congressional district is a congressional district in the U.S. state of Colorado. The district is located in the north-central part of the state and encompasses the northwestern suburbs of Denver including Boulder and Fort Collins. The district also includes the mountain towns of Vail, Granby, Steamboat Springs, and Idaho Springs. Redistricting in 2011 moved Larimer County, including the cities of Fort Collins and Loveland, to the 2nd from the 4th district. Meanwhile, redistricting in 2021 moved Loveland back to the 4th district and Broomfield and western Jefferson County to the 7th district.

Larimer County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 359,066. The county seat and most populous city is Fort Collins. The county was named for William Larimer, Jr., the founder of Denver.