Patrick Aloysius O'Boyle (July 18, 1896 – August 10, 1987) was an American Catholic prelate who served as the first resident Archbishop of Washington from 1948 to 1973. He was elevated to the cardinalate in 1967.

Patrick O'Boyle was born on July 18, 1896, in Scranton, Pennsylvania, to Michael and Mary (née Muldoon) O'Boyle, who were Irish immigrants. His father was originally from Glenties, County Donegal, and in 1889 came to the United States, where he settled at Bedford, New York. His mother moved to New York City from County Mayo in 1879, and married O'Boyle in December 1893. Shortly afterwards, the couple moved to Scranton, where Michael became a steelworker; they had a daughter who died during infancy in 1895.

Patrick O'Boyle was baptized at St. Paul's Church in Scranton. Following Michael's death in January 1907, he helped support his mother by becoming a paperboy. He dropped out of school in 1910 to pursue a full-time career with the Bradstreet Company, but entered St. Thomas College in 1911. In addition to his studies, he there served as class librarian and editor of the monthly magazine The Aquinas.

O'Boyle graduated from St. Thomas' as valedictorian in 1916, and then began his studies for the priesthood at St. Joseph's Seminary in Yonkers, New York. During his time at St. Joseph's, he developed a close friendship with Reverend James McIntyre, a future cardinal. McIntyre tutored O'Boyle in Latin and invited him to spend holidays with his family. One of O'Boyle's professors was Reverend Francis P. Duffy, a famed US Army chaplain of World War I.

O'Boyle was ordained a priest for the Archdiocese of New York by Archbishop Patrick Hayes on May 21, 1921. The next day he celebrated his first mass at St. Paul's Church in his native Scranton. After his ordination, the archdiocese assigned O'Boyle as a curate at St. Columba's Church in the Chelsea section of Manhattan. While there, he organized St. Joseph's Society for teenage boys, beginning with about 300 members, and instituted parish dances.

In 1926, Hayes named O'Boyle as director of the Catholic Guardian Society, a division of Catholic Charities that handled orphans and foster children; during this time, he also resided and did pastoral work at the Church of the Holy Innocents in Manhattan. Sheila Wickouski identifies social concerns, labor rights, and racial equality as having been O'Boyle's key issues. O'Boyle furthered his studies at the New York School of Social Work in Manhattan from 1927 to 1932. He also taught child welfare at Fordham Graduate School of Social Service in Manhattan from 1930 to 1934.

In 1933, O''Boyle was asked to organize Catholic Charities in New York. O'Boyle worked closely with the federal Works Progress Administration to find jobs for young people in the archdiocese. He then served as director of the Mission of the Immaculate Virgin in Staten Island, New York, from 1936 to 1943.

The Vatican raised O'Boyle to the rank of a privy chamberlain in 1941 and a domestic prelate in 1944. He was named director of the War Relief Services of the National Catholic Welfare Conference in 1943, then director of Catholic Charities in New York in August 1947.