In his family, Silvio Antoniani was cardinal and Sebastiano Gualterio had been Bishop of Viterbo, Papal Nuncio to France and the Council of Trent.

Later he was made referendary of the Tribunals of the Apostolic Signature and Rector of La Sapienza University, Rome.

Carlo Gualterio was created cardinal deacon in the consistory of 2 March 1654 by Pope Innocent X and opted for the deaconry of S. Pancrazio.

He resigned the government of the archdiocese before 30 April 1668 in favour of his nephew Giannotto Gualterio.

Promoted to the order of Cardinal Priest on 25 December 1668 with the title of Sant'Eusebio, he participated in the Papal Conclave of 1669–1670.