Bowen was born near Rochester, Indiana, to Vernie Bowen and Pearl Irene Wright. His father's side of the family was deeply religious and originally came from Ohio. Vernie Bowen graduated from Valparaiso University and was a teacher for 43 years. Vernie Bowen also owned a hardware store in Leiters Ford, was a trustee for Aubbeenaubbee Township, President of the Woodlawn Hospital Board of Trustees, and President of the Leiters Ford Merchants Association. His father was a Scottish Rite Freemason and a member of the Independent Order of Odd Fellows. In 1915, Vernie Bowen married Pearl Irene Wright, whose family was also from Ohio and involved with the Independent Order of Odd Fellows. Otis Bowen is a distant relative of George H. W. Bush through two brothers who immigrated to New England from Somerset, England.