William Ezra Jenner (July 21, 1908–March 9, 1985) was a U.S. Republican politician from the State of Indiana.

Jenner was born in Marengo, Crawford County, Indiana. He graduated with a Law degree from Indiana University in 1930, and set up practice in Paoli, Indiana. In 1934 he was elected to the Indiana State Senate, serving as Minority Leader 1937-9, and Majority Leader and President Pro Tempore 1939-41; in 1942 he resigned his seat to serve in the military upon U.S. entry to World War II. In 1944 he returned from overseas action to fill an entry in the U.S. Senate; however, he was not a candidate for election to the full term. In 1946 he was elected to the Senate, and re-elected in 1952. In Congress, he was a follower of Joseph McCarthy and the leader of principle attacks upon the Democratic Party. In 1958 he was not a candidate for re-nomination. In 1959 he resumed legal practice in Bedford, Indiana, where he died on March 9, 1985.