Robert Carter Nicholas (January 10, 1787 – December 24, 1856) was a United States senator from Louisiana.

[4][5] Nicholas joined the United States Army in 1808, receiving a commission as a Captain in the 7th Infantry Regiment.

[10][11] After his military service, Nicholas relocated to Kentucky, and in 1821 received an appointment as U.S. Indian Agent to the Chickasaw Nation.

[14] Nicholas was elected as a Jacksonian (later a Democrat) to the U.S. Senate to fill the vacancy caused by the resignation of Senator-elect Charles E.A.

[19] He married Susan Adelaide Vinson, and their children included a daughter, Mary.