 Braun's son from a previous marriage is Kieron Dwyer,<ref></ref> and Byrne became Dwyer's stepfather when the boy was 13 until Byrne divorced his mother.They only lived together for a short time as the young Dwyer soon moved to Los Angeles to live with his father.Byrne encouraged Dwyer's aspirations to be a cartoonist and assisted in landing Dwyer's first professional job drawing "Batman" #413 (Nov. 1987).<ref></ref>

Since 2015, Byrne no longer attends any conventions regularly and makes rare public appearances.<ref></ref> He made an exceptional appearance at the Fan Expo Boston 2018<ref></ref> where he spoke at two events, both titled "Spotlight on John Byrne" on August 11 and 12, and an autograph signing with William Shatner.