The Thirty-first Oklahoma Legislature was a meeting of the legislative branch of the government of Oklahoma, composed of the Senate and the House of Representatives. It met in Oklahoma City from January 7, 1967, to January 7, 1969, during the term of Governor Dewey Bartlett. This was the first Oklahoma state legislature that met under new requirements approved by voters in 1966 that the legislature hold annual, 90-day legislative sessions. Clem McSpadden served as the President pro tempore of the Oklahoma Senate and Rex Privett served as the Speaker of the Oklahoma House of Representatives.