|Full name||Wílliam Ruben Martínez Carreras|
|Date of birth||January 13, 1928|
|Place of birth||Pueblo Victoria, Uruguay|
|Date of death||December 28, 1997 (Aged 69)|
|Playing position||Right Half-Back/Midfield|
|* Senior club appearances and goals counted for the domestic league only and correct as of April 2008.
† Appearances (Goals).
Martínez came through the youth team of local side Sportivo Alba de Victoria and signed on as a youth player for Nacional in 1962. After playing for Nacional at various youth levels and for the first team he joined Racing Club de Montevideo in 1947.
It was with Peñarol that Martínez enjoyed most of his success at the club level. During his time with the club he captained the team to five consecutive league titles (1958–1962), two Copa Libertadores (1960 & 1961) the Copa Intercontinental in 1961 and four consecutive editions of the Copa Uruguay (1958–1961).
- Primera División Uruguaya: 1943 & 1946
- Torneo de Honor: 1943 & 1946
- Torneo Competencia: 1945
- Copa de Confraternidad Escobar – Gerona: 1945
- Copa Aldao: 1946
With Rampla Juniors
- Torneo Competencia: 1950
- Torneo Cuadrangular: 1953
With C.A. Peñarol
- Primera División Uruguaya: 1958, 1959, 1960, 1961, 1962
- Torneo Competencia: 1956 & 1957
- Torneo de Honor: 1956
- Cuadrangular Tournament: 1955, 1957, 1959, 1960
- Cuadrangular in Mexico: 1957
- Copa Libertadores: 1960 & 1961
- Intercontinental Cup: 1961
- World Cup Champions Squads 1930 – 2002
- (Spanish) A primeira grande zebra do Mundial
- FIFA.com – William Martinez at fifa.com