|See||Archdiocese of Fermo|
|Title||Archbishop of Fermo Emeritus, Cardinal priest of Sant'Eusebio|
|Period in office||October 5, 1654—before April 30, 1668|
|Previous post||Rector of La Sapienza University, Rome|
|Created cardinal||March 2, 1654|
|Date of birth||1613|
|Place of birth||Orvieto, Italy|
|Date of death||January 1, 1673 at age of 59|
|Place of death||Rome, Italy|
Gualterio was born at Orvieto. Among his relatives, Silvio Antoniani was cardinal and Sebastiano Gualterio had been Bishop of Viterbo, Papal Nuncio to France and the Council of Trent. He was related to Donna Olimpia Maidalchini and Pope Innocent X Pamphilj, and also grand-uncle of Cardinal Filippo Antonio Gualterio and great-grand-uncle of Cardinal Luigi Gualterio.
Carlo Gualterio was created cardinal deacon in the consistory of March 2, 1654 by Pope Innocent X and opted for the deaconary of S. Pancrazio. From 1672 to 1673 he was Camerlengo of the Sacred College of Cardinals.
He was elected Archbishop of Fermo on October 5, 1654. He took part in the Papal conclave of 1655 and in that of 1667. He resigned the government of the archdiocese before April 30, 1668 in favour of his nephew Giannotto Gualterio. Promoted to the order of Cardinal Priest on December 25, 1668 with the title of Sant'Eusebio, he participated in the Papal Conclave of 1669-1670.