Lucius Marcius Philippus (c. 141 – c. 73 BC) was a Roman orator and an important politician of the late Roman Republic. His strenuous opposition to the reforms of Marcus Livius Drusus during his consulship of 91 BC was instrumental in the outbreak of the disastrous Bellum Italicum, the Social War. He did well under the Marian government during the mid-80s BC, holding the high office of censor in 86 BC. However, he took advantage of the political amnesty offered by Sulla during the civil war of 83 BC and changed sides, along with other Marians of later importance, such as Marcus Aemilius Lepidus (cos. 78) and Marcus Junius Brutus (tr. pl. 83), Publius Cethegus, and Pompey.