William A. Reilly

William "Bill" A. Reilly, 92, of Rockford, passed away at home surrounded by family on February 1, 2026. Bill was born in Erie, Pennsylvania, on December 15, 1933, to Daniel J. Reilly, Jr., and Frances Maria Helena (Haack) Reilly. From his father, Bill learned the value of humor and a flair for performance—and quite possibly a lifelong appreciation for dessert. From his mother, he learned the importance of a strong Catholic faith, to which he remained deeply committed and actively devoted throughout his life. Bill’s early life emphasized family, church activities, Boy Scouts, and acting in school productions — interests that continued through his life.

He married his neighborhood sweetheart, Mariann T. Healy, in Chicago in 1957, and together they shared 68 years of marriage until Bill’s passing. They enjoyed cruising and won the “Marriage Game Show” on two separate cruises. Deeply committed to family life, Bill and Mariann raised four children. He organized annual family vacations—often extended driving trips that introduced new states each year. Disney World became an especially cherished destination, first enjoyed with his children and later with his grandchildren. Boating was a passion, and Bill spent countless hours pulling family members on water skis. He also loved swimming and claimed to never be tired of playing Sharks and Minnows with his grandchildren. Of special note were Bill’s extraordinary efforts to attend all his children’s and grandchildren’s sporting events, concerts, and shows, to name just a few thousand.

Bill began working for Johnson Service Company, later Johnson Controls, during his senior year at the Illinois Institute of Technology. After graduating as a mechanical engineer, he continued his career with Johnson Controls until his retirement as a branch manager in Rockford, Illinois. He believed strongly in mentoring engineers and sales professionals, particularly emphasizing the importance of professional ethics. He was instrumental in the establishment of the local chapter of ASHRAE (the American Society of Heating, Refrigerating, and Air-Conditioning Engineers).

Bill was deeply involved at Holy Family Catholic Church in Rockford. Of special note was his service on the building committee that oversaw construction of the original church building. He was a longtime lector, especially appreciated for his ability to proclaim the Word of God clearly, reverently, and with meaning.

Bill had a lifetime commitment to Scouting. As a young man, Bill earned the Boy Scout Ranger Award, at that time the highest honor issued by the Exploring Division of the Boy Scouts of America. He encouraged his children’s involvement in Scouting by volunteering extensively as an adult leader. Over multiple decades, he served Holy Family Church’s Pack 139 and Troop 139 as Cubmaster, Scoutmaster, Troop Committee Chairman, and in many other roles. Through an active outdoor program and engaging meetings, he provided countless Scouts with character development and leadership skills. He had a particular love for the Boundary Waters Canoe Area. The Diocese of Rockford recognized his contribution to Scouting by presenting him with the prestigious St. George Award.

In 1982, Bill returned to acting through Rock Valley College’s Starlight Theatre in Rockford. He performed in productions at both the Starlight Theatre and the Studio Theatre for forty years. He was notable for his role as Jacob in three separate productions of Joseph and the Amazing Technicolor Dreamcoat. He especially enjoyed acting alongside his children and grandchildren, with Mariann often involved in front-of-house roles. Rock Valley College once recognized Bill and his family as the Starlight Theatre Family of the Year.

Bill is survived by his beloved wife, Mariann; his children William “Bill” A. (Peg) Reilly II of Belvidere, Illinois; Susan M. Gillenwater of Rockford, Illinois; Kevin P. (Renee) Reilly of Chicago, Illinois; and Brian K. Reilly of Stuart, Florida; his grandchildren Jennifer Reilly; William “Bill” (Rachel) Reilly III; Michael “Mike” (Cydney) Reilly; Grant Gillenwater; Bridget (Trent) Emerson; Shane (Kayla) Gillenwater; Elena Reilly; Adrian Reilly; Noelle Reilly; and Thomas “Tom” Reilly; as well as seven great-grandchildren. Bill was predeceased by his parents, Daniel and Frances, his siblings Daniel J. (Marion) Reilly III, Lawrence H. F. (Irene) Reilly; Betty Anne (Charles “Chuck”) Iffland; Mary Jane (William “Bill”) Smith and his son-in-law Stanley “Stan” Gillenwater and daughter-in-law Patti Reilly. He was deeply loved and will be profoundly missed.

A Funeral Mass will be held at 2:00 p.m. on Saturday, February 7, 2026, with visitation from 1:00 p.m. until the time of Mass, at Holy Family Catholic Church, 4401 Highcrest Road, Rockford, Illinois 61107. Private interment will be held at a later date.

In lieu of flowers, please consider memorials to the Poor Clare Colettine Nuns, Corpus Christi Monastery, 2111 South Main Street, Rockford, Illinois 61102. To send condolences online or share memories, please visit www.fitzgeraldfh.com.