Born in Evergreen Park, he attended Marist High School in Chicago and the College of St. Francis in Joliet. He studied theology at Our Lady of Guadalupe Seminary in Elmhurst, Pennsylvania, and at Mount St. Mary's Seminary in Emmitsburg, Maryland. He was ordained to the priesthood by Bishop Thomas G. Doran on May 17, 2003.
Father Parker's first assignment was as parochial vicar at Holy Cross, Batavia, and also taught religion at Aurora Central Catholic High School (2003-2006). He became administrator of St. Mary Parish in East Dubuque in 2006, becoming pastor of that parish in 2007, and also of Nativity of the Blessed Virgin Mary Parish in Menominee in 2009.
His most recent assignment has been as pastor of St. Mary Parish in DeKalb since 2013.