Samuel Penniman Bates (1827–1902) was an American educator, author, and historian. He is noted for his reference works on the American Civil War, including his multi-volume History of the Pennsylvania Volunteers, 1861–1865 which remains the standard reference for the commonwealth's regimental histories and unit rosters.
Bates was born in Mendon, Massachusetts. He graduated at Brown University in 1851. In 1860 he was made deputy State superintendent of schools and in 1866, he was made historian of the Commonwealth of Pennsylvania. His numerous lectures and reports did much to further the cause of education.
His educational works include Lectures on Moral and mental Culture (1860), Liberal Education (1865), Method of Teachers' Institutes (1862), and History of Colleges in Pennsylvania.
- Discourse, life and character of John Barker (1860)
- History of the Pennsylvania Volunteers, 1861–1865 (1869)
- Lives of the Governors of Pennsylvania (1873)
- Martial Deeds of Pennsylvania (1875)
- Memoir of Oliver Blachly Knowles: Late colonel of the 21st Pennsylvania Cavalry and brevet-brigadier general (1878)
- Battle of Gettysburg (1878)
- Battle of Chancellorsville (1882)
- A Brief History of the One Hundredth Regiment (Roundheads) (1884)
- History of Erie County; Containing A History of the County, Its Townships, Towns, Villages, Schools, Churches, Industries, etc. (1884)
- History of Crawford County, Pennsylvania (1885)
- A Biographical History of Greene County, Pennsylvania (1888)