Samuel William Preston (6 April 1842 – 15 January 1865) was an officer in the United States Navy during the American Civil War.

Born near London, Ontario, Canada, Preston was appointed midshipman from the state of Illinois on 4 October 1858.

Graduating first in his class, 9 May 1861, he was appointed Acting Master on 4 October 1861, and Lieutenant 1 August 1862.

Ordered to the North Atlantic Blockading Squadron as flag-lieutenant to Rear Admiral David Dixon Porter, he participated in the attacks on Fort Fisher on 24–25 December 1864, and 15 January 1865.

He was killed while leading an amphibious assault of U.S. sailors and marines against the fort on the latter date.