John Saint Ryan (né Barker; 27 March 1953 – 3 April 2025) was an English actor, horse trainer and equestrian. He appeared in supporting roles in film and television. His more memorable characters include Fergus in the 1997 Fox television series Roar and Myles Standish in Disney's 1994 adventure drama film Squanto: A Warrior's Tale.
Ryan made his acting debut in 1983 in G.B.H. and soon landed a small role in the hit British soap opera Emmerdale (then known as Emmerdale Farm) as Jameson. Ryan appeared in theatre productions of Far from the Madding Crowd and A Streetcar Named Desire, and in supporting roles in films and television series including Coronation Street (as Charlie Whelan), Buffy the Vampire Slayer, General Hospital, Murder, She Wrote, Cybill, and the made-for-TV movie The Heidi Chronicles. Ryan also played the main antagonist Cyborg in American Cyborg: Steel Warrior.

Ryan moved to California in the early 1990s. He owned and operated the "Red Rose Ranch", a working horse and cattle ranch near Inyokern, California, where he raised, boarded, and sold horses. He trained horses and riders in both dressage and western riding; Ryan's specialty was the doma vaquera style of western riding, a Spanish form of competitive Western pleasure riding. He won multiple national and international titles in the sport, and wrote books and produced videos on the doma vaquera style.