Benjamin Mayberry Prentiss (November 23, 1819 – February 8, 1901) was an American soldier and politician. He fought in the Mexican-American War and the American Civil War, rising to the rank of major general.

The Civil War
After the Civil War, he became a lawyer and was later appointed to postmaster by President Benjamin Harrison and was re-appointed by President William McKinley. He was a leader in the Republican Party of Missouri.