Bishop John Charles Dunne was born in Brooklyn on October 30, 1937. He received his formal education at St. Boniface School, Elmont, St. Francis Prep and Cathedral College, both in Brooklyn, and Immaculate Conception Seminary, Huntington, NY. He was ordained to the priesthood on June 1, 1963.

After serving as associate pastor of St. Anthony of Padua Church, East Northport, Bishop Dunne was assigned to be associate director of the diocesan Confraternity of Christian Doctrine (now the Office of Catechesis and Worship) which oversees the religious education of young people outside the Catholic school system and the continuing education of adults. He also served as associate director of the Family Life Bureau which included conducting programs to prepare couples for marriage. In 1970 Bishop Dunne was appointed spiritual director at Immaculate Conception Seminary where he served until he was appointed associate Vicar for Religious, the office which acts as liaison between the bishop and the women and men Religious who serve in the diocese. In 1974 Bishop Dunne became associate pastor of Corpus Christi Church, Mineola.

In 1978 he was named director of the Priest Personnel Office which involves acting as liaison between the bishop and the priests of the diocese as well as facilitating the assignment of priests. Bishop Dunne also served on the Priest Personnel Policy Board. In 1984 he was appointed pastor of Blessed Sacrament Church, Valley Stream.

On October 25th, 1988, Pope John Paul II appointed him auxiliary bishop of the Rockville Centre Diocese and he was ordained on December 13th, 1988 at St. Agnes Cathedral in Rockville Centre. He served on the National Conference of Catholic Bishops’ Committee on Science and Human Values and was also a member of the Anglican-Roman Catholic Dialogue in the United States. He previously chaired the Committee on Women in Society and in the Church and served on the Committee for Marriage and Family Life and the Lay Ecclesial Ministry Subcommittee for the organization.

Bishop Dunne’s parents, Mark and Helen Dunne, are both deceased. His only brother, the Reverend Mark J. Dunne, was also a priest of the Diocese of Rockville Centre; he died in 1982.