Robert Frederick Trisco was born on November 11, 1929 in Chicago, Illinois, the son of Richard and Harriet Rose (Hardt) Trisco.

He attended Saint Mary of the Lake Seminary in Mundelein, Illinois, graduating with a bachelor's degree in 1951. He later attended the Pontifical Gregorian University in Rome, earning a licentiate of sacred theology degree in 1955 and a doctoral degree in ecclesiastical history in 1962 with his dissertation titled, "The Holy See and the Nascent Church in the Middle Western United States, 1826-1850". He was ordained a priest in 1954 for the Archdiocese of Chicago.

Msgr. Trisco began his service at The Catholic University of America in 1959. He was a professor of Church History and served as the Kelly-Quinn Distinguished Professor of Church History from 1999 until his retirement in 2000, when he was granted emeritus status. Msgr. Trisco proudly served as the dissertation director for 25 successful doctoral projects in Church History, including the Ph.D. dissertation To Teach, Govern, and Sanctify: The Life of Edwin Vincent O'Hara by then-Father Timothy Dolan, current Cardinal Archbishop of New York.

Msgr. Trisco also had a long record of service to the academic discipline of Church History and to the wider Catholic Church. He served as the Executive Secretary of the American Catholic Historical Association from 1961 to 2009 succeeding Msgr. John Tracy Ellis in the position, and Managing Editor of The Catholic Historical Review from 1963 to 2005. Then-Fr. Trisco was a peritus at the Second Vatican Council (1962-1965), the president of the American subcommittee of the International Commission for Comparative Ecclesiastical History (currently known as the International Commission for History and Studies of Christianity) from 1978 to 1980, and he remained an assesseur for the commission through 2010. He was a member of the International Joint Commission for Theological Dialogue between the Catholic Church and the Orthodox Church from 1999 to 2006, a member of the Anglican-Roman Catholic consultation in the United States from 2002 to 2007, a member of the advisory committee of the Friends of the Archives of Congregation for Doctrine of the Faith since 1999, a member of the Pontifical Committee for Historical Sciences from 1982 to 2009, and an honorary member of the Accademia di San Carlo (Milan) since 1986.

In recognition of his many contributions to the Church and in academia, Msgr. Trisco was named an Honorary prelate with the title of monsignor in 1992 and a Protonotary Apostolic Supernumerary in 2005, presented to him by his former student Archbishop Dolan. He was named a Decorated Knight of the Equestrian Order of the Holy Sepulchre of Jerusalem in 1993 and promoted to the rank of Knight Commander in 1998. He was awarded an honorary Doctor of Humane Letters degree from Belmont Abbey College in 1992 and was given the Centennial Award by the American Catholic Historical Association in 2019.

Most recently, Msgr. Trisco pledged $650,000 in support of the John K. Mullen of Denver Memorial Library and the study of Church History at Catholic University. The majority of this bequest will establish The Msgr. Robert Frederick Trisco Church History Library Endowment. Msgr. Trisco's gift will allow the University to continue to add to its impressive collection and ensure that future historians have the materials they need to continue his life's work. The remainder of his bequest will be used to process archival materials he is bequeathing to Mullen Library, including his personal papers and correspondence, as well as papers from the American Catholic Historical Association and The Catholic Historical Review.

Lying in State, Sunday, August 6, 2023 from 3:00 p.m. to 5:00 p.m. in Curley Hall of The Catholic University of America, 3861 Divinity Way, Washington, DC 20064; Funeral Mass, Monday, August 7, 2023, 10:30 a.m. in the Crypt Church of the Basilica of The National Shrine of the Immaculate Conception, 400 Michigan Ave. NE, Washington, DC 20017, Celebrant Cardinal Timothy Dolan.  Mass of Christian Burial, Friday, August 11, 2023, 10:00 a.m. at St. Celestine Church of St. Mother Theodore Guerin Parish, 3020 N. 76th Court, Elmwood Park, IL 60707, Celebrant Cardinal Blase Cupich.  Interment to follow at St. Joseph Cemetery, River Grove, Illinois.  Funeral arrangements have been entrusted to Francis J. Collins Funeral Home, Silver Springs, MD and The Elms Funeral Home, Elmwood Park, IL. For information 708-453-1234