List of United States Senate elections in Colorado

United States Senate elections in Colorado occur when voters in the U.S. state of Colorado select an individual to represent the state in the United States Senate in either of the state's two seats allotted by the Constitution. Regularly scheduled general elections occur on Election Day, coinciding with various other federal, statewide, and local races.

Each state is allotted two U.S. Senators elected to staggered six-year terms, which were originally selected by the state legislature. The Senate is divided into three classes to stagger the terms of its members such that one-third of the Senate would be up for re-election every two years. Upon Colorado's admission to the Union in 1876, the state was assigned a Class 2 seat and a Class 3 seat, first elected in 1876. Since the passage of the Seventeenth Amendment in 1913, U.S. Senators are elected directly by the voters of each state. Special elections may be held to fill mid-term vacancies to elect an individual to serve the remainder of the unexpired term.

The list below contains results from all U.S. Senate elections held in Colorado after the passage of the Seventeenth Amendment, sorted by year. The next scheduled election for the Class 2 seat is in 2026, while the Class 3 seat will hold its next election in 2028.

Class 2

 * County results of Class 2 elections since 2002

Class 3

 * County results of Class 3 elections since 2004