Sherman Day (February 11, 1806 – December 14, 1884) was an American politician and mining engineer from California.

He was one of the founders of the College of California and the son of president of Yale University, Jeremiah Day.

He also worked as a civil engineer and planned and supervised the construction of Plymouth Church.

[4] Sherman Day's Historical Collections of Pennsylvania is considered one of the most important documentations of early histories of Pennsylvania, mostly because it included individual histories for all the counties within the Keystone State.

As well, it contained a series of wonderful images (produced by Sherman as well) of all parts of the Keystone State.

[citation needed] In 1849, Day moved to San Francisco and worked as a civil and mining engineer.

[1][2][citation needed] He served as editor pro tempore of the newspaper The Pacific.

[4] In 1868, Day was appointed as the Surveyor General of California with the help of Senator Cornelius Cole.

[2][4] They had six children, Henry, Clinton, Roger Sherman, Harriet King, Martha Elizabeth and Jane Olivia.