Diogo Gil Moniz (formerly Diogo Gil) was a Portuguese nobleman.
He was the eldest son of Gil Aires and wife Leonor Rodrigues.
He was Vedor of the Fazenda of Infante Ferdinand, Duke of Viseu, brother of King Afonso V of Portugal and father of King Manuel I of Portugal.
He married Leonor da Silva, daughter of Rui Gomes da Silva, of the Lords of a Chamusca, and wife Branca de Almeida, and had: