Satyrus of Milan () was an Italian Catholic administrator born in Augusta Treverorum, who was the brother of Ambrose of Milan and Marcellina.
He was born around 331 at Augusta Treverorum (modern Trier, Germany), moved to Rome with his family and was subsequently trained as a lawyer.
Appointed prefect to one of the Roman provinces, he resigned his post when Ambrose became Archbishop of Milan in order to assume administration of the secular affairs of the archdiocese.
He died unexpectedly at Milan in 378 and was eulogised by his brother with the funeral sermon, On the Death of a Brother (De excessu fratris Satyri). The church of Santa Maria presso San Satiro in Milan refers to him.