Rey de Oro (Japanese: レイデオロ foaled 5 February 2014) is a Japanese Thoroughbred racehorse. As a juvenile in 2016 he was undefeated in three races including the Grade 2 Hopeful Stakes and was rated one of the best two-year-old colts in Japan. In the following year he won the Tokyo Yushun and Kobe Shimbun Hai and finished second in the Japan Cup. At the end of the season he was rated one of the best three-year-old colts in the world and took the JRA Award for Best Three-Year-Old Colt. As a four-year-old in 2018 he won the Sankei Sho All Comers and took the autumn edition of the Tenno Sho.