Jon Plumer (born March 1, 1955) is an American Republican politician and retired salesman. He was a member of the Wisconsin State Assembly, representing the 42nd Assembly district since winning a June 2018 special election until his retirement in 2025.
Plumer won a special election, held on June 12, 2018, against Democrat Ann Groves Lloyd. He subsequently won a rematch with Groves Lloyd in the 2018 general election.