Charles S. Kelsey was a member of the Wisconsin State Senate and the Wisconsin State Assembly.
Kelsey was born on October 7, 1822 in Perry, New York. His older brother, William H. Kelsey, was a member of the United States House of Representatives and his younger brother, Edwin B. Kelsey, was also a member of the Assembly and the Senate.
Before moving to Montello, Wisconsin in 1854, Kelsey married Lucretia Bacon in 1840. They would have four children before her death in 1869. Among them were Otto Kelsey, who became a member of the New York State Assembly, and Julia Kelsey, who became Postmistress of Montello.
Kelsey was a member of the Senate from 1862 to 1864 and of the Assembly in 1867, 1873 and 1880. He was a Republican.