Lowndes County is a county on the eastern border of the U.S. state of Mississippi. As of the 2020 United States Census, the population was 58,879. Its county seat is Columbus. The county is named for U.S. Congressman William Jones Lowndes.

William Jones Lowndes was an American lawyer, planter, and politician from South Carolina. He represented the state in the U.S. Congress from 1811 to May 8, 1822, when he resigned for health reasons.