Count Gustaf Horn (October 22, 1592 - May 10, 1657) was a Swedish soldier and politician, appointed Privy Councilor in 1625, Field Marshal in 1628, Governor General of Livonia in 1652 and Lord High Constable in 1653. In the Thirty Years' War (1618-1648), he was instrumental as acommander in securing victory at the Battle of Breitenfeld, in 1631.

He married Kristina Oxenstierna (1609-1631), in 1628, and fathered Agneta Horn (1629-1672).

See also: List of Swedish politicians, List of Swedish military commanders, List of Swedish wars