Guillermo Rivas Rowlatt (December 25, 1926 – March 19, 2004) was a Mexican character actor known for portraying "El Borras" in the Telesistema Mexicano sitcom Los Beverly de Peralvillo (1968–1973).
His first role in a film was in 1938, aged only eleven years old, The Cemetery of the Eagles starring Jorge Negrete.
While sharing stages with Mario Moreno 'Cantinflas', Silvia Pinal and Enrique Rambal, he made more over 100 television and movie appearances.
He received his nickname "El Borras" after starring in the TV series Los Beverly de Peralvillo, which also inspired two movies.
Rivas appeared in films of the 1960s, 1970s, and 1980s, generally comedies, but he was also capable of playing dramatic roles.