Robert Edward Kilbridge was born on December 9, 1918, in Chicago, Illinois. He was the son of Joseph T. Kilbridge and Lillian Volker. After attending Catholic elementary schools in Chicago, he entered Quigley Preparatory Seminary for the Archdiocese of Chicago. After one year, he transferred to Fenwick High School in Oak Park, Illinois and continued his college studies at Providence College with other students preparing for the novitiate. He received a B.A. degree from Providence College in 1940

In August 1940, he received the habit from Peter O'Brien, O.P., first Provincial of the Province, at the Dominican House of Studies in River Forest, Illinois, and was given the religious name Antoninus. On August 5, 1941, he made simple profession to Peter O'Brien, O.P. He completed his philosophy and theology studies at the Dominican House of Studies, during which time he took solemn vows at summer camp in Menominee, Michigan in 1944. He was ordained a priest on June 5, 1947, in the chapel of the Dominican House of Studies in River Forest, Illinois. After ordination, he was sent to Saint Pius V Priory where there was a "preaching institute" to prepare young friars for the Mission Bands.

His first assignment was Assistant Pastor at Holy Name Parish in Kansas City, Kansas from 1949-1955. This pastoral assignment would start a lifelong ministry of pastoral care, but he would have a three-year ministry in initial formation. In 1955, he was sent to the novitiate at Saint Peter Martyr Priory in Winona, Minnesota to be the Novice Master for the Cooperator Brothers. In 1958, he would return to pastoral ministry at Saint Vincent Ferrer Parish in River Forest and in 1963, he was appointed pastor of Saint Hyacinth Parish in Amarillo, Texas. After his term of six years, the Provincial sent him to our foreign mission in Ghana and later to Nigeria. In addition to his pastoral duties, he served as Master of

Students at the House of Studies in Ibadan, Nigeria for six years.

In 1986, he returned to the United States where he was a chaplain for the Dominican Sisters Motherhouse at Grand Rapids, Michigan and later for the Monastery of the Blessed Sacrament at Farmington Hills, Michigan. In 1991, he would return to pastoral ministry at Saint Mary Star of the Sea Parish in Chicago and in 1998, he would become an Associate Pastor at Saint Vincent Ferrer Parish in River Forest. In 2008, he moved to Saint Pius V Priory because he required more care due to advanced age. One year later he would move to the Resurrection Life Center in Chicago, where he would receive the medical care he needed due to his declining health.

On March 5, 2011, he died at the Resurrection Life Center. The Office of the Dead and the Mass of Christian Burial were held at Saint Vincent Ferrer Church in River Forest, Illinois and he was buried in the plot at All Saints Cemetery in Des Plaines, Illinois. His funeral was attended by a large number of friars and laity who he had served throughout his life as a pastor.