Gilliat is a surname. Notable people with the surname include:
Bruce Gilliat, American businessman Cathy Gilliat-Smith, English hockey player John Saunders Gilliat, British banker Martin Gilliat, British soldier Richard Gilliat, English cricketer Rosemary Gilliat, Canadian photojournalist Sidney Gilliat, British film director Walter Gilliat, English footballer
See also Gilliat River, Queensland, Australia Gilliatt, a surname