Fr. Shawn Aaron was born in Ridgecrest, CA, on January 25, 1968. He is the oldest of four children, with three younger sisters. On April 29, 1978, his family entered the Catholic Church. They later relocated to Modesto, CA, where he attended Central Catholic High School, lettering in several sports: football, basketball, baseball, and track.

After completing high school, Fr. Shawn attended Modesto Junior College, where he studied liberal arts and ran track. In 1989-90, he served as a team leader for the National Evangelization Teams (NET) and traveled throughout the United States providing retreats for students. After NET he began working with St. Paul’s Outreach (SPO), in St. Paul, Minnesota, their mission is to build transformational communities that form missionary disciples for life.

In 1991, he joined the Legionaries of Christ in Cheshire, Connecticut. He studied at the Pontifical Athenaeum Regina Apostolorum in Rome, Italy, and received degrees in philosophy (1996) and theology (2002). On Christmas Eve, 2002, Father Shawn was ordained to the priesthood at Colegio Internacional Legionarios de Cristo in Rome, Italy.

After ordinations, he served as development director for the Legionaries of Christ for several years. From 2007-2009, he also served as retreat director for Our Lady of Santa Clara retreat center in Cupertino, CA.

From 2009 through 2010, he was appointed President of Southern Catholic College in Dawsonville, GA. From 2010 – 2017, he was the National Chaplain of The Lumen Institute, based in Manhattan. He serves on the Board of Directors for Divine Mercy University and the Lumen Institute.

He was appointed the North American Territorial Vicar General for the Legionaries of Christ in 2017, a role he held until being named the North American Territorial Director on March 30, 2020 (effective April 1, 2020). He was appointed to a second three-year term on March 21, 2023. His second term began on July 1, 2023.