The British Schools of Montevideo were founded in 1908. Six years later, the school's first alumni decided to create a social and sport club: The Old Boys Club. Female alumni followed suit some years later and founded the Old Girls Club in 1937.
After a friendly rugby union game against former players of the British y Montevideo CC in 1948, Old Boys decided to start a rugby section. Only two years later, Old Boys won the first ever national title in 1950.
Rugby would quickly become the club's main sport and the sport for which the club is mostly known today. The club is one of the most successful in Uruguay, having won the Campeonato Uruguayo 15 times.