Publius Servilius Casca Longus (84 BC – c. 42 BC) was one of the assassins of Gaius Julius Caesar. He and several other senators conspired to kill Caesar, which they did on 15 March 44 BC. He was one of the first to attack, and stabbed Caesar in the neck.
At the time of the conspiracy, he held office in the Tribune of the People. After Caesar was dead, he ran from Rome. Casca joined Marcus Junius Brutus and Gaius Cassius Longinus, the leaders of the assassins, during the Liberators' civil war against the Second Triumvirate, Caesar's former supporters. He committed suicide during this war.
Casca is remembered on a coin along with Brutus, where they both have their names engraved in the metal. A bearded figure appears on the coin next to Casca's name, though this is widely considered to be the Roman god Neptune.