J. O. Tobin (March 28, 1974 – 1994) was an American-bred thoroughbred racehorse. As a two-year-old, he was sent to Europe, where he won his first three races, including the Richmond Stakes and Champagne Stakes, and was the highest-rated juvenile of the season in Britain. In the following year, he was transferred to the United States, where he recorded his most famous victory as he ended the undefeated streak of the Triple Crown winner Seattle Slew with a win in the Swaps Stakes.