Gian Giacomo Teodoro Trivulzio (Milan, 1597 - Milan , August 3, 1656) was an Italian Cardinal from Milan, who held several high functions in service of the Spanish Crown.
He was the son of Carlos Manuel Trivulzio, count of Melci, who died when Gian Giacomo was still very young, and Catherina Gonzaga. In 1615 he married Giovanna Maria Grimaldi, daughter of Hercule, Lord of Monaco.
They had two daughters and one son :
When his wife died in 1620, Gian Giacomo entered the Church. In 1629, he became cardinal.
In 1642 he became Viceroy of Aragon, and Grandee of Spain.
He participated in the Papal conclave, 1644, which finally chose Pope Innocent X, and in the Papal conclave, 1655, which elected Pope Alexander VII.
Between 1647 and 1649 he was Viceroy of Sicily and between 1649 and 1651 Viceroy of Sardinia. In April 1656 he became interim Governor of the Duchy of Milan, a post he held until his death. He died in Milan on August 3, 1656 and was buried in the family vault in the Santo Stefano church.