Publius Servilius Casca Longus (died c. 42 BC) was one of the assassins of Julius Caesar. He and several other senators conspired to kill him, a plan which they carried out on 15 March, 44 BC. Afterwards, Casca fought with the liberators during the Liberators' civil war. He is believed to have died by suicide after their defeat at the Battle of Philippi in 42 BC.