John Joseph O'Connor, 73, a retired professor of history at Georgetown University and a founder and former president of the Catholic Interracial Council here, died Monday at Georgetown University Hospital. Dr. O'Connor had suffered a stroke last week and died of pneumonia.

Dr. O'Connor, who was a member of the National Association for the Advancement of Colored People and the National Conference of Christians and Jews, served as spokesman during the late 1940s and 1950s for representatives of political, religious, PTA and civic groups to promote programs to improve Christian race relations. For this work he received the James J. Hoey award in 1949.

Dr. O'Connor also received a NAACP citation in 1950 for his contributions in the field of human rights.

Born in Washington, he graduated from Georgetown University, where he earned a law degree and his doctorate in history in 1936. Dr. O'Connor was one of the founders of the Catholic Evidence Guild of Washington during the 1930s, and has been a faculty member of Georgetown University from 1946 until 1967, when he retired.

While at Georgetown, he was a professor of history and a lecturer at the Foreign Service School. He was a former editor of Commonweal and was managing editor of Logistics Magazine for the War Department from 1942 to 1946.

Among the books Dr. O'Connor authored are "Twenty-Five in Ireland" and "Catholic Revival in England."

He was a member of the Heights Association and Opus Dei, a group of layman and priests.

Survivors include five daughters, Clare Coulter, of Oxon Hill, Sister John Ellen, of Philadelphia, Ellen Bligh of Rockville, Brigid Frost of Arlington, and Lucy, of Bethesda; two sons, John Daniel, of Seattle, Wash., and Damian, of Columbia, Md.: a sister. Sister Thomas Aquinas, of Alexandria, and 11 grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to Opus Dei in northwest Washington.