James Joseph Moore born on 23 October 1919 in Chicago, Illinois, was the third of four children born to John J. and Elsie Josephine (Kenneally) Moore. His siblings were: William John Moore, Patricia Mary Moore Flotkoetter, and Thomas Bernard Moore. His parents and siblings all preceded him in death. Father Moore attended Maternity of the B.V.M. Grammar School from 1925-32 in Chicago. His high school education began at DePaul Academy then he transferred and graduated from Saint Mel High School in 1936. After attending DePaul University for one year, he went on active duty in the United States Navy from 1943-45 then was honorably discharged on 11 September 1945 as an Ensign. He was part of the 7th Fleet in Southwest Pacific and the Far East. From 1945-49 he was on inactive duty.

After Father Moore was free from military service, he entered the Dominican Province of Saint Albert the Great receiving the habit and the religious name Gregory at Saint Peter Martyr Priory in Winona, Minnesota on 29 September 1949 from Master General Father Emmanuel Suarez, O.P. One year later on 30 September 1950 he professed his first vows also at Saint Peter Martyr Priory in the hands of Father Timothy Sparks, O.P., then Socius to the Master General. He began his studies for the priesthood at the Dominican House of Studies (Aquinas Institute of Philosophy), River Forest, Illinois earning a B.A. in Philosophy in 1953. This same year on 30 September he professed his solemn vows at Saint Rose Priory in Dubuque, Iowa, again in the hands of the Master General Father Emmanuel Suarez, O.P.

Gregory continued his studies in Theology for the priesthood at Saint Albert College in Oakland, California, location of the house of studies for the Province of the Holy Name, for the next three years. He was ordained to the priesthood on 10 June 1955 at Saint Mary's Cathedral in San Francisco, California by Bishop Merlin J. Guilfoyle. The following year he returned to Saint Rose Priory for a year of further study.

Father Moore's first assignment was to our new mission in Africa. From 1957-64 he was parochial vicar of Saint Dominic's Church in Yaba, Lagos State, Nigeria. In 1964 he returned to the province and became director of the Saint Dominic Mission Society through the provincial office. In 1967 he returned to Nigeria and did missionary work there until 1982. This work included: establishing a new religious house and serving as novice master in Ibadan, Oyo State (1967-68); parochial vicar at Saint Dominic's Church, Yaba, Lagos State (1968-69); pastor/chaplain at the University of Ife, Ile-Ife (1969-71); student master and superior in Ibadan, Oyo State (1971-74); pastor of Saint Vincent Church and director of Catechetical Training Center, Malumfashi (1974-75); pastor of Saint Theresa Church, Funtua (1975-78); parochial vicar of Saint Dominic's Church, Yelwa (1978-79); and

secretary to Bishop Michael J. Dempsey, O.P., Holy Family Cathedral, Sokoto (1979-82). In 1982 he returned to the Province from the mission in Nigeria.

From 1982 to 2001 Father Moore served in a variety of places as pastor, chaplain, parish supply and parochial vicar in Chicago, Illinois; Madison, Wisconsin; Minneapolis, Minnesota; and Grand Rapids, Michigan. Father Gregory was always willing to help out for however long he was needed in any given place. He was a tremendous help to many of the dioceses and archdioceses the province serves. Many times, he would relieve and fill in for priests on sabbatical or extended time away from the parish. He brought great joy and a missionary spirit with lots of stories everywhere he went. In 2001 he was assigned to limited service at Saint Pius V Priory in Chicago, though he continued to help many parishes in the area. He lived at Saint Pius Priory until his health declined to the point that he had to be transferred to Resurrection Life Center in Chicago in 2015.

He died peacefully at Resurrection Life Center on 16 April 2016. At his death he was the oldest living member of the province at age 96. Father Moore had a large extended family including nieces, nephews and cousins. Many were in attendance at his funeral.

Services were held at Saint Vincent Ferrer Church in River Forest, Illinois on Friday, 22 April 2016. Mass of Christian Burial was at 10:00AM preceded by Sung Morning Prayer at 9:00AM. Father James V. Marchionda, O.P., Prior Provincial, presided and Father William Kenneally, Father Moore's first cousin, preached. Funeral arrangements were handled by Smith-Corcoran Funeral Home. He was buried in the Dominican Section at All Saints Cemetery in Des Plaines, Illinois.