Rev. John Patrick Raynor, S.J., was born October 1, 1923 in Omaha, Nebraska. The second of nine children, Raynor was known to his family as "Don," due to his childhood difficulty pronouncing the letter J. After attending St. Margaret Mary and Our Lady of Lourdes parochial grade schools, Raynor entered the Jesuit-run Creighton Preparatory High School. His experience with Jesuit educators led Raynor to enter the Society of Jesus at St. Stanislaus Seminary in Florissant, Missouri on August 17, 1941. In 1947, Raynor earned a bachelor's degree in Greek and Latin from St. Louis University, followed closely by a master of arts in 1948 from the same institution. After teaching for several years at St. Louis University High School, Raynor matriculated to St. Mary's College in Kansas for his theological studies before being ordained to the priesthood on June 16, 1954. Father Raynor continued his studies at St. Joseph's Hall in Decatur, Illinois and the University of Chicago where he completed his doctorate in higher education with a dissertation entitled "The Encouragement of Research at Five Jesuit Institutions."

In 1960, Rev. Raynor began his Marquette career as an instructor of education and an assistant dean in the College of Liberal Arts. In 1962, he was appointed Vice-President of Academic Affairs. Three years later, on September 9, 1965, Father Raynor became the twentieth president of Marquette University. He would continue as president of Marquette until August 14, 1990, the longest tenure of any Marquette University president. During his twenty-five years as Marquette's president, Raynor led the university through successful expansions of its campus, degree programs, and endowment. Often referring to his role as a "salesman" for Marquette, Father Raynor devoted considerable time and attention to soliciting donations and to increasing awareness of Marquette within the local and academic communities. During his tenure, Marquette completed several large fundraising campaigns. Under Raynor's leadership, Marquette underwent several administrative changes. In 1967, the Marquette School of Medicine was separated from the university and was recreated as the Medical College of Wisconsin. Two years later, the university Board of Trustees was expanded to include, for the first time, lay members. As university president, Raynor dealt with academic and administrative concerns from across Marquette's colleges and schools. Father Raynor and his administration faced many social issues of national and international resonance. His office handled concerns over civil rights, the Vietnam War, abortion, Vatican II, free speech, and academic freedom, among others. About these and other concerns, Raynor communicated with diverse groups, including students, alumni, benefactors, parents, faculty, and Jesuits. As president of Marquette, Father Raynor served an influential role in the community. He sat on several boards and committees, including the directorial boards of Kimberly-Clark and the American Lung Association of Wisconsin. Father Raynor also represented Marquette in many local and religious associations of higher education.

After his retirement from the presidency, Raynor held the post of university chancellor from August 15, 1991 until his death from complications of melanoma on November 14, 1997, at 74 years of age. Father Raynor's impact on Marquette is enduring, and the university contains several tributes to his lasting legacy. In September 1991, an endowed faculty chair was created in his honor. The university's Raynor Library opened in 2003.