John "Jack" Stephen Sirotniak Sr.

John Stephen Sirotniak, of Arlington, Virginia, passed away peacefully on Sunday, October 19, 2025, at the age of 86, in the presence of his loving family. He was born in Jersey City, NJ, on July 3, 1939.

“Jack” as he was known to family, friends and colleagues, grew up in Jersey City, NJ. He graduated from Saint Peter’s Prep in 1957, and from Saint Peter’s College in 1961. He was commissioned as a 2nd Lieutenant in the United States Marine Corps shortly after and married the love of his life Mary K. (Johnson) in 1962.

During his 20-year Marine Corps career, Jack served as an Infantry Officer and Communications Officer and had a variety of roles and assignments. He completed two combat tours in Vietnam. He also served at duty stations including Camp Lejeune NC, Quantico VA, Okinawa Japan, and Arlington VA, before retiring from active service at the rank of Major in 1981. After the Marine Corps, Jack remained in Northern Virginia for the next 30 years, where he worked with the Department of the Navy as a defense contractor for Milcom Systems Corporation, CACI, and Booz Allen Hamilton.

Jack was a faithful and active parishioner at Saint Charles Borromeo Catholic Church for over 53 years and volunteered a great deal of his time and talents in support of the parish. He was humble in words and large in actions and had a quick and witty sense of humor as well as a razor-sharp intellect. Jack was an amazing handyman and casual carpenter who designed and completed many home projects. He had a host of other talents which included playing the guitar, painting, drawing and sketching. He was an avid reader and master at crossword puzzles. Jack was also an amazing baker and chef of Slovak cuisine and known for his Kolache (nut roll) and Babka.

In addition to his many talents, Jack was a lifelong athlete, distance runner, cyclist and swimmer. He completed 14 marathons, including three finishes at Boston, and numerous mini triathlons. His athletic discipline and drive inspired many of his family members to follow his example.

Jack embodied the Marine Corps motto, Semper Fidelis – “Always Faithful”, and he will be remembered with love, gratitude, and respect by his family and all who knew and loved him.

Jack is survived by his beloved spouse of 63 years, Mary (Johnson) Sirotniak, children Annie Sirotniak (Brian Whitehead), John Sirotniak (Emma), Marie Sirotniak, Michael Sirotniak (Anh) and Karen Sirotniak; his grandchildren Cameron, Kyle, Catherine, Hans, Jude and Noah; brother-in-law Tony Jaswinski, and his many cousins, nieces, nephews, great-nieces and great-nephews.

He was predeceased by his parents Stephen Sirotniak and Clare Mary (Kerekes), his sister Mary Clare Jaswinski, and his grandson Vincent.

Jack’s family will welcome family and friends for a Celebration of Life on Friday October 31, from 4:00-8:00 pm at Murphy Funeral Home, 4510 Wilson Blvd, Arlington. A Funeral Mass will be celebrated on Saturday November 1, at 11:00 am at Saint Charles Catholic Church, 3304 Wilson Blvd, Arlington. Burial will take place a later date at Arlington National Cemetery.

In lieu of flowers, the family requests that donations be made to Ronald McDonald House (ronaldmcdonaldhouse.org). Prayer requests and check donations can be made directly to Poor Clare Monastery of Mary, Mother of the Church, 2505 Stone Hedge Drive, Alexandria VA 22306 (poorclaresofalexandria.org)