He was out of the mare Seximee, a daughter of the 1954 Preakness Stakes winner Hasty Road.
Nonoalco was purchased and raced by María Félix, a Mexican actress and wife of French financier Alex Berger.
Trained by François Boutin, at age two Nonoalco had an outstanding year in racing.
As a three-year-old, he won the British Classic, the 2000 Guineas at Newmarket Racecourse, beating the odds-on favourite Apalachee into third place.
Retired to stud having won four Group One races, Nonoalco stood in France in 1975 and in Ireland from 1976 through 1981 before being shipped to Japan, where he stood until his death at age twenty-one in 1992.