The long life of Patrick Cardinal O'Boyle was spent heavily immersed in the Catholic Church with particular attention devoted to charitable institutions, building projects, and racial integration. The son of devout Irish immigrants, he was born on July 18, 1896 in Scranton, Pennsylvania, where his parents raised him. Early in his life, he attended the school attached to the parish church called St. Paul's Church. Although in 1910 he had to temporarily drop out of school to help support his family - an extended household of iron workers and stone cutters - he graduated in 1912 from St. Thomas Preparatory High School. O'Boyle continued on at St. Thomas' collegiate program and received a college degree four years later. Shortly thereafter, he became a seminarian at St. Joseph's Seminary in Yonkers, New York, and was ordained in 1921.

Father O'Boyle's first assignment as a priest was at St. Columba's Parish in New York. While maintaining his responsibilities as an assistant in the parish, in the mid-1920s, he began helping with the organization of the Annual Fundraiser for the New York Catholic Charities, which was a massive endeavor; his attention to detail and hard work ethic earned him sole supervision of the fundraiser in 1926. In that same year, the archbishop of New York asked him to run the Catholic Guardian Society of Catholic Charities - an organization that helped care for teenage orphans and foster children - as its newest director. Understanding the need for specialized training in such an important position, O'Boyle began a graduate program at the New York School of Social Work in 1927, and graduated in 1932. In a similar vein, in 1933, he helped establish a new school at The Catholic University of America devoted to social work training. The financial skills he had developed along with his experience in social work explains O'Boyle's appointment in 1936 as director of Mt. Loretto, NY, on Staten Island, which was the site of the home of the Immaculate Virgin for the Protection of Homeless and Destitute Children. With the assistance of the newly hired James J. Norris as a financial assistant, O'Boyle introduced massive reforms to help integrate the many facets of the institutions extensive grounds. Again, demonstrating his ability to improve an organization's internal administration, he left Mt. Loretto in 1943 to become the Director of the newly founded War Relief Services (WRS). The goal he and his small staff took up was to help overseas soldiers, POWs, and refugees materially and spiritually through the remainder of and following the end of World War II. It was during his time at WRS that built many relationships in Washington and across the Atlantic, as he had to make numerous trips to the nation's capital to gain government approval to send materiel into Europe. By 1947, the nature of the WRS had shifted, and it was apparent that O'Boyle's superiors believed that his abilities were better placed elsewhere, explaining his transfer to the office of the Director of Catholic Charities in New York. He was, however, unable to settle into his new post because by the end of 1947, he was informed that the Vatican had selected him to become the head of the newly established Archbishopric of Washington, D.C.

As the bishop of the newly established archdiocese, O'Boyle devoted a significant amount of time and resources into obtaining new diocesan properties for the construction of new churches, schools, hospitals and convents to accommodate the growing population of the D.C. area. In 1956, he was able to raise sufficient funds for the construction of Providence Hospital. The other aspiration he gave equal weight to was racial integration. He worked against the segregated nature of the D.C. Catholic Church and the general culture in D.C. and southern Maryland of Jim Crow rules. Upon his arrival in his new archdiocese in the late 40s and early 50s, Bishop O'Boyle strove to desegregate parishes, schools, and hospitals despite significant resistance. Perhaps the greatest stride he took for both of these endeavors was his founding of John Carroll High School, which, from its inception, admitted black students.

When called to the Second Vatican Council in the mid-twentieth century, O'Boyle was determined not to remain a passive participant. Early in the council proceedings, he was voted to the Commission on Seminaries, Studies, and Catholic Schools, in which he worked vigorously to improve the methods of training and the curricula for students at all levels of Catholic training, even making an intervention to his fellow council fathers about seminary curricula. He was also vocal in other areas important to him; he delivered two other conciliar interventions concerned with Jewish relations and racial equality. Many of the arguments he presented contributed to the adjustment or addition of material in the decrees of the council. Two years after the conclusion of the council, O'Boyle received the red hat and joined the College of Cardinals.

After the conclusion of the council, O'Boyle focused his attention to three issues back in his archdiocese: the rate of change in liturgical change, the civil rights movement, and the controversy emerging at The Catholic University of America. First, O'Boyle attempted to keep a firm grip on the reigns of liturgical reform. Although he believed liturgical reform was necessary, he did not want unsanctioned experimentation to threaten the authority of his office or to lead an uninformed laity astray. O'Boyle had also returned his focus to race relations, following the conclusion of the council. As a resolute supporter of racial justice, he advocated government assurance of civil rights and built many relationships with civil rights leaders. Perhaps one of the most difficult challenges he faced occurred in his last years as acting archbishop, when a controversy over the Catholic Church's stance on birth control, in 1938, pulled him into a conflict with a number of the priests in his see, including members of the faculty at The Catholic University of America, publicly advocated the ability to use birth control. Two years after the very public dispute had been resolved, he retired in 1973. Despite his retirement, he remained active by attending conferences, ceremonies, and travelling to visit family and friends. In 1987, after falling ill with pneumonia and suffering problem complications with his kidneys, Cardinal O'Boyle died at the age of 91.