The 1966 United States Senate election in Oklahoma took place on November 8, 1966. Democratic Senator Fred R. Harris ran for re-election to a second term, and his first full term. After winning an easy victory in the Republican primary, he faced attorney Pat J. Patterson, the Republican nominee, in the general election. Patterson wasn't viewed as a strong candidate against Harris,[1] but the national Republican landslide helped make the race somewhat close. Harris ended up narrowly defeating Patterson to win his final term in the Senate.