Octavian was the name of Augustus (63 BC – 14 AD) before he became Emperor of Rome.

Octavian or Octavianus may also refer to:

• Octavian (horse), a British horse
• Octavian, an octopus villager from the video game series Animal Crossing
• Octavian (rapper), French-British rapper
• Octavian (romance), a 14th-century Middle English poem
• Octavians, financial commissioners in 16th century Scotland
• Octavian, a character in Der Rosenkavalier
• Octavian or Gus, a mouse in Cinderella
• Octavian, a Camp Half-Blood character
• Octavius, Latin praenomen (first name)

• Octavianus (poet), Latin poet of the 6th century AD
• Octavian Abrudan (born 1984), Romanian footballer
• Octavian Belu (born 1951), Romanian gymnastics coach
• Octavian Bodișteanu (born 1977), Moldovan politician
• Octavian Chihaia (born 1981), Romanian footballer
• Octavian Cotescu (1931–1985), Romanian actor
• Octavian Drăghici (born 1985), Romanian footballer
• Octavian Goga (1881–1938), Romanian politician, poet, and playwright
• Octavian Grigore (born 1964), Romanian footballer
• Octavian Guțu (born 1982), Moldovan swimmer
• Octavian Ionescu (footballer, born 1990), Romanian football center back
• Octavian Ionescu (footballer, born 1949), Romanian football midfielder
• Ștefan Octavian Iosif (1875–1913), Romanian poet and translator
• Octavian Nemescu (born 1940), Romanian composer
• Octavian Ormenișan (born 1992), Romanian footballer
• Octavian Paler (1926–2007), Romanian writer and activist
• Octavian Popescu (born 1938), Romanian footballer
• Octavian Popescu (born 1985), Romanian footballer
• Octavian Smigelschi (1866–1912), Austro-Hungarian Romanian painter
• Octavian Codru Tăslăuanu (1876-1942), Romanian magazine editor and politician
• Octavian Țîcu (born 1972), Moldovan politician
• Octavian Utalea (1868–?), Romanian politician
• Octavian Vintilă (born 1938), Romanian fencer
• Octavian Zidaru (born 1953), Romanian fencer
• Octavian, the Antipope Victor IV (1159–1164)