Robert P. Tiller (born December 11, 1949 in Amsterdam, The Netherlands) is a Canadian Thoroughbred racehorse trainer. A resident of Brampton, Ontario, he has long been one of the top trainers at Toronto's Woodbine Racetrack. He has won four training titles at Woodbine Racetrack, earned three Sovereign Awards for Outstanding Trainer and was inducted into the Canadian Horse Racing Hall of Fame in 2008. In 2008, he was inducted in the Canadian Horse Racing Hall of Fame. On June 19, 2020, at Woodbine Racetrack, Tiller won his 2000th race.