The 2024 Colorado's 4th congressional district special election was held on June 25, 2024, to fill the vacant seat in Colorado's 4th congressional district. The winner will serve in the United States House of Representatives for the remainder of the 118th United States Congress. The seat became vacant on March 22, 2024, when Ken Buck resigned from Congress.
The 4th district is based in eastern Colorado and the exurbs of Denver, taking in Highlands Ranch, Loveland, and Castle Rock. It is considered a safe Republican district and the most strongly Republican district in Colorado.
Nominees were not chosen via primary election. Instead, each party's nominee was selected by a committee of party leaders and elected officials in the 4th congressional district.
Republican nominee Greg Lopez easily defeated Democratic nominee Trisha Calvarese with 58.4% of the vote.
Republican nomination.
The Republican nominee was chosen on March 28, 2024, by a 111-member committee. Two candidates in the election, Holtorf and Lynch, served on the committee.
Endorsements.
 ;templatestyles src="Endorsements box/styles.css"/ ; Greg Lopez
State legislators
 ;templatestyles src="Endorsements box/styles.css"/ ;Jerry Sonnenberg "(eliminated)"
State legislators
 ;templatestyles src="Endorsements box/styles.css"/ ;Declined to endorse
U.S. representatives
Democratic nomination.
The Democratic nominee was chosen at a meeting on April 1, 2024.
References.
 ;templatestyles src="Reflist/styles.css" / ;
External links.
Official campaign websites