Benedetto Lomellini (1517 – 24 July, 1579) was an Italian Roman Catholic cardinal and bishop.
Benedetto Lomellini was born in Genoa in 1517, the son of a rich noble family. He received a doctorate in law.
He practiced as a lawyer and became a cleric in Genoa. He later moved to Rome, becoming a Referendary of the Apostolic Signatura. On September 27, 1543, he became an abbreviator de parco maiori. He was made a secretary apostolic on December 1, 1551. The pope also made him a domestic prelate. On July 27, 1562, he became a member of the Apostolic Camera. He was made praefectus annonae on November 13, 1562. He accompanied Cardinal Carlo Carafa during his legation to Philip II of Spain.
Pope Pius IV made him a cardinal deacon in the consistory of March 12, 1565. He received the red hat and the deaconry of Santa Maria in Aquiro on May 15, 1565.
On July 6, 1565, he was elected Bishop of Ventimiglia. He was transferred to the see of Luni-Sarzana on September 7, 1565. On the same day, he opted for the titular church of Santa Sabina. He was consecrated as a bishop by Cardinal Clemente d'Olera in San Pietro in Montorio on November 21, 1565.