The club is also known as Galo da Comarca, roughly meaning County's Rooster.
In 1951, XV de Jaú won the Campeonato Paulista Second Level, beating Linense, of Lins in the final. The club then played the relegation/promotion play-off against Jabaquara, which was the last placed team of Campeonato Paulista First Level. XV de Jaú won the first leg, but was defeated in the second leg. In the third match against Jabaquara, the club beat its opponent and was promoted to the following year's Campeonato Paulista First Level.
In 1976, for the second time, the Campeonato Paulista Second Level was won by the club.
In 1979, the club competed for the first time in the top level of the Brazilian Championship, finishing in the 56th place.
Three years later, in 1982, XV de Jaú competed again in the Brazilian football's top level league, finishing this time in the 20th position, ahead of clubs such as Internacional, Cruzeiro and Atlético Paranaense.
In 1988, the club competed in the third level of the Brazilian Championship, but was eliminated in the first stage of the competition, finishing in the last place of its group.