Marcus Julius Philippus Severus, also known as Philippus II, Philip II and Philip the Younger (238–249) was the son and heir of the Roman Emperor Philip the Arab by his wife Roman Empress Marcia Otacilia Severa. According to numismatic evidence, he had a sister called Julia Severa or Severina, whom the extant literary sources do not mention and a brother, Quintus Philippus Severus.
When his father became emperor in 244 he was appointed Caesar. In 247 he became consul, and later elevated by his father to the rank of Augustus and co-ruler.
His father was killed in battle by his successor Decius in 249. When news of this death reached Rome, he was murdered by the Praetorian Guard. He died in his mother's arms, aged eleven years.