Junior's Senior football team played in the Mexican Amateur League prior to the professionalization and development of the Primera División de México in 1943.

"Junior Club" was founded in 1906 by initiative of Father Camilo Crivelli (1874–1954), who was in charge of the local church by then.

In 1908 Pablo Alexanderson, who lived in San Pedro de los Pinos, a small village in the outskirts of Mexico City, bought the club and mainly used it for the practice of tennis and baseball although football continued to being practised.

In order to build a competitive club, players from all society and races were signed by Junior.

Junior also obtained its best record and placed just six points behind the champion, Club España, who would go on to dominate the league for the next 20 years.