Samuel Alexander Mudd I, M.D. (December 20, 1833 – January 10, 1883) was an American physician who was convicted and imprisoned for aiding and conspiring with John Wilkes Booth in the 1865 assassination of U.S. President Abraham Lincoln. He was pardoned by President Andrew Johnson and released from prison in 1869. Despite repeated attempts by family members and others to have it expunged, his conviction has never been overturned.

Born in Charles County, Maryland, Mudd was the fourth of ten children of Henry Lowe and Sarah Ann Reeves Mudd. He grew up on "Oak Hill", his father's tobacco plantation of several hundred acres which was located 30 miles (48 km) southeast of downtown Washington, D.C., and which was worked by 89 slaves.