Sebastianus was a Roman general who was killed at the Battle of Adrianople during the Gothic War.

The Emperor Valens called for Sebastianus' assistance during the Gothic War. Under Sebastianus' leadership, the Romans wrested back some of the initiative by conducting a semi-guerilla type campaign against the Goths. However Valens disregarded Sebastianus' advice to wait until the forces of the Emperor Gratian arrived before bringing the Goths to a battle. Sebastianus perished along with Valens in the battle.^[1][2]