The Bellum Octavianum (Latin for "War of Octavius") was a Roman republican civil war fought in 87 BC between the two consuls of that year, Gnaeus Octavius and Lucius Cornelius Cinna. Cinna was victorious by late 87 BC.

Hostilities broke out after Octavius opposed Cinna's attempts to distribute the Italian citizens enfranchised after