Rex Barnett (born October 22, 1938) is an American politician. He was an officer of the Missouri State Highway Patrol for 32 years in Troop H. He was a member of the Republican Party. Between 1994 and 2002, he was a member of the Missouri House of Representatives. He was born in Laredo, Missouri.
In 2012, Barnett's grandson, Matthew Barnett, was arrested for the rape of the then fourteen-year-old Daisy Coleman. However prosecutors declined to pursue charges and the records were sealed. Many people believed the case was closed because of Barnett's connection.