Thomas Joseph Donlan, was born on September 15, 1917, in Chicago, Illinois, the eldest of the two children of Anne Marie (Sheehan) and Thomas Joseph Donlan. He grew up in Oak Park, Illinois, and attended St. Catherine of Siena Grammar School and Fenwick High School. Upon graduation from high school he spent two years at Providence College, Providence, Rhode Island, before deciding to enter the Dominican novitiate of the Province of St. Joseph.

In August of 1937 he began his novitiate at St. Rose of Lima Priory, Springfield,

Kentucky, where he received the religious name of Cajetan. He made his first profession there on August 16, 1938, and was assigned to St. Thomas Aquinas Priory, River Forest, Illinois, to begin his philosophical studies. When the new province of St. Albert the Great was formed in December 1939, he chose to be affiliated with it. Father Donlan made his final profession at St. Thomas Aquinas Priory on August 16, 1941, and was ordained there on June 8, 1944, completed his theological studies in 1945 and was awarded the S.T.Lr. degree.

From 1945 through 1952 he was assigned to Fenwick High School, Oak Park, Illinois, where he served as chair of the Department of Religion. For two years (1946-48) he interrupted his teaching to pursue graduate studies at the Pontifical Faculty, Dominican House of Studies, Washington, D. C., and obtained the doctorate in theology in 1952. For one year he taught theology at Marycrest College, Davenport, Iowa, and then joined the Dominican faculty at St. Rose of Lima Priory, Dubuque, Iowa, where he was professor of moral theology (1953-57) and professor of homiletics (1954-60). During 1963 -64 Father Donlan was a Fulbright Research Scholar in Theology at the Institute Catholique de Paris, an experience which established lasting ties with France and the French Dominicans. He was one of the founders of The Priory Press, serving as vice-president (1953-60) and then as president (1960- 65). When The Priory Press moved to Chicago in 1964, Father Donlan moved with it, and helped to establish St. Louis Bertrand House which served as a publications house for the Province.

In 1969 Father Donlan began a nearly fifteen-year period in which he served the Church nationally and internationally in various capacities. He assisted the United States Catholic Conference as Director of Research and Development in Religious Education (1969-72) in Washington, D.C.; was editor of the Catholic Digest (1972-75) in Minneapolis, Minnesota; served as Rome Correspondent for the National Catholic News Service (1975-77) in Rome, Italy; and returned to the United States to serve as Officer for Public Education, Catholic Relief Services (1977-83) in New York Cit y. From 1983 until early 1997 he resided first at St. Stephen Parish (1977-89) and the at St. Agnes Parish (1989 -97) in New York. During this time he was the Sole U. S. Agent for the French Dominican publishing house, Les Editions du Cerf; assisted Father Patrick Peton, C.S.C., with the Family Rosary Crusade (1983-84) and served as chaplain to the Catholic Actors Guild of America (1985-96). At the age of 80 he began limited service and took up residence at St. Vincent Ferrer Priory, River Forest, Illinois.

In addition to these ministries Father Donlan served the Province of St. Albert the Great as Provincial Director of Education (1964-66) and as a member of the Provincial Council (1969-73). For two years (1967 - 69) he was chair of special commission appointed by the Master of the Order for the Publication of Books in the Order of Preachers. He was a member of the College Theology Society which he served as vice president (1955-56), president (1956-68) and director (1958-60). In 1986 he was elected to the Fenwick High School Hall of Fame.

Father Donlan was stopping in Paris after having spent some time with his nephew in Rome when he was unexpectedly taken sick early on the morning of February 26, 1999.

Having suffered an apparent heart attack, he soon slipped into a coma and died later that morning at the American Hospital of Neuilly-sur-Seine, near Paris, without regaining consciousness. A memorial funeral liturgy was celebrated on March 3rd at St. Vincent Ferrer Church, River Forest, Illinois, and on March 20, 1999, his remains were interred with a private ceremony in the Dominican plot at All Saints Cemetery, Des Plaines, Illinois.