Samuel Addison Oliver (July 21, 1833 – July 7, 1912) was an American pioneer, lawyer, judge, and politician from western Iowa.
He was born near Washington, Washington County, Pennsylvania, in 1834, and received a classical education at the common schools and West Alexandria Academy. He graduated from Washington College in Washington, Pennsylvania (now Washington & Jefferson College) in 1850. He taught school for two years in Arkansas, returning to Pennsylvania to study law. He married Hannah Towne on January 1, 1854. He was admitted to the bar, and moved to Iowa in 1857, taking up his residence at Onawa, in Monona County, where he began practice law. He was county supervisor in 1861, and served as provost marshal during the Civil War.
Oliver was elected to the Iowa House of Representatives of the Tenth Iowa General Assembly in 1863, to represent the district composed of the counties of Carroll, Crawford, Monona and Sac. He was a delegate to the Republican National Convention in 1864. He became a prominent member of the Iowa House, and at the close of his term was elected to the Iowa Senate for the Forty-fifth District, composed of fifteen counties in the northwestern part of the State, serving from 1865 to 1867. He was then chosen as circuit judge, and was twice re-elected, serving from 1868 to 1875.