David Rice Atchison statue at Clinton County Courthouse

David Rice Atchison (August 11, 1807 – January 26, 1886) was a mid-19th century Democratic United States Senator from Missouri. He served as President pro tempore of the United States Senate for six years. He is best known for the claim that for one day (March 4, 1849) he may have been Acting President of the United States.

Atchison was a prominent pro-slavery activist and Border Ruffian leader, deeply involved with violence against abolitionists and other free-staters during the "Bleeding Kansas" events.