1900 in Argentine football saw English High School members joining again to the team to request their affiliation. Quilmes Rovers also returned under its new name "Quilmes Atlético Club". Both teams replaced Lobos and Lanús Athletic.
English High School win its first Argentine championship. The international Tie Cup (where teams from Buenos Aires, Rosario and Montevideo took part) was played for the first time, being won by Belgrano AC.
The championship continued with the 4 team league format, with each team playing the other twice.