Mark Alan Messmer[1] (born December 16, 1967) is an American politician who has served as the U.S. representative for Indiana's 8th congressional district since 2025.

A member of the Republican Party, he previously represented the 48th district in the Indiana Senate from 2014 to 2024, including as majority leader of the chamber from 2018 to 2022.

[4][5] Questions were also raised due to Leucadia National hiring Mark Lubbers to promote the deal.

[7] In 2022, Messmer sponsored a bill that bans the foreign ownership of agricultural land in Indiana.

[11] He defeated former U.S. Representative John Hostettler in primary by a wide margin of roughly 20 points.