Octavius Valentine Catto (February 22, 1839 – October 10, 1871) was a black educator, intellectual, and civil rights activist in Philadelphia.
He became principal of male students at the Institute for Colored Youth, where he had also been educated.
Born free in Charleston, South Carolina, in a prominent mixed-race family, he moved north as a boy with his family.
He became educated and served as a teacher, becoming active in civil rights.
As a man, he also became known as a top cricket and baseball player in 19th-century Philadelphia, Pennsylvania.
Catto became a martyr to racism, as he was shot and killed in election-day violence in Philadelphia, where ethnic Irish of the Democratic Party, which was anti-Reconstruction and had opposed black suffrage, attacked black men to prevent their voting for Republican candidates.