The 2018 Colorado Attorney General election took place on November 6, 2018, to elect the next attorney general of Colorado.

Incumbent Republican Cynthia Coffman did not run for re-election, instead opting to run for governor. The Democratic Party nominated Phil Weiser, who subsequently defeated Republican nominee George Brauchler in the general election. Weiser's victory marked the first time a Democrat became attorney general since Ken Salazar (in office from 1999 to 2005) and the second time a Democrat won the office since the 1970s.

Arapahoe County District Attorney George Brauchler won the Republican nomination unopposed.

The Democratic primary was contested between Phil Weiser, former dean of the University of Colorado Law School, and Joe Salazar, a state representative. Prior to the primary, outgoing John Hickenlooper took the "extraordinary move" of publicly endorsing Weiser. Salazar's campaign had received support from democratic socialist U.S. Senator Bernie Sanders and left-wing organization Our Revolution.

Weiser and Salazar qualified for the Democratic primary ballot. Attorney Amy Padden did not qualify.

Weiser narrowly defeated Salazar by a 50.43% to 49.57% margin.

Attorney William F. Robinson, III was the Libertarian nominee.

Weiser won the general election by a 6.5% margin of victory.