The 1968 United States Senate election in Oklahoma was held November 3, 1968. Incumbent Democratic U.S. Senator Mike Monroney was running for re-election to a fourth term, but was defeated by Republican Henry Bellmon. This is the last time that a Senator from Oklahoma lost re-election.
This election was the first time since 1942 that a Republican won a United States Senate election in Oklahoma and the first time since 1920 that a Republican won this seat.