On July 27, 2016, eleven days after his 60th birthday, Doyle was found unresponsive in his Las Vegas home, and declared dead shortly thereafter. Condolences were received from his former co-stars, including from Bruce Boxleitner, who wrote that he was "so devastated at the news of the untimely death of my good friend". Babylon 5 creator J. Michael Straczynski released a statement, saying "Regardless of whatever was going on in his life, whether it was marital issues, a broken arm, forced couch-surfing with Bruce and Andreas or other problems, he never once pulled a prima donna on us; he showed up every day on time, knew his lines, and insisted that the guest cast live up to the standards of the main cast." The Clark County Coroner's Office later stated that Doyle died from natural causes, with complications from chronic alcoholism being a contributing factor.