Harold (foaled 1876 inPennsylvania) was an AmericanThoroughbredracehorse.

Harold was a chestnut horse bred byAristides Welch who owned both his sire and his dam. Sired byLeamington, a four-timeLeading sire in North America, he was out of themare,Maggie B. B. who produced two other Classic winners:Iroquois, a full brother to Harold who became the first American-bred horse to ever winEngland's renownedEpsom Derby, plus the coltPanique byAlarm who won the 1884Belmont Stakes.

Harold was acquired by the prominentNew York stable owner,George L. Lorillard. He entrusted his race conditioning to future U.S. racing Hall of Fame trainerR. W. Walden who would call Harold the best horse he had ever trained

Racing at age two, Harold won important races in 1878 and is regarded historically as theAmerican Champion Two-Year-Old Male Horse. At age three, he won thePreakness Stakes, but in the ensuingWithers Stakes he suffered a ruptured blood vessel from which he never fully recovered and won only one more race before being retired tostud.^[1]

Harold died after serving just one full season at stud.