Charles Rainsford Jennison also known as "Doc" Jennison (June 6, 1834 – June 21, 1884) was a member of the anti-slavery group during Bleeding Kansas. He was also a famous Jayhawker, and a member of the Kansas State Senate in the 1870s. He later served as a Union colonel and as a leader of Jayhawker militias during the American Civil War.