Philip II ( Marcus Julius Severus Philippus; born 237 – died 249 at age 12), also known as Philip the Younger, was the son and heir of the Roman emperor Philip the Arab by his wife Marcia Otacilia Severa. 

When his father became emperor in 244, the 7-year-old Philip was appointed caesar. In 247 he became consul, and was later elevated by his father to the rank of augustus and co-ruler.  The thousandth anniversary of the founding of Rome occurred during their reign and great games and spectacles were planned for the celebration.

Ancient historians say that Philip the Arab and Philip II were both killed in battle by Decius in 249.  Modern historians say that when news of Philip the Arab's death reached Rome, Philip II was murdered by the Praetorian Guard at the age of twelve.  Some argue that Philip II was sole ruler of the empire for the fall of 249.