The 1966 Wyoming gubernatorial election took place on November 8, 1966. Incumbent Republican Governor Clifford Hansen declined to seek a second term, instead opting to run for the U.S. Senate. Stanley Hathaway, the former Goshen County Prosecuting Attorney, won the Republican primary, and faced attorney Ernest Wilkerson, the Democratic nominee, in the general election. Despite the unfavorable national environment for Democratic candidates, Wilkerson was able to improve on Democrats' performance from the 1962 election, but not enough to defeat Hathaway, who won the election by a decisive margin.