Gregorio Byington Duvivier is a Brazilian actor, comedian and poet. He is known by his works in film and theater, being one of the members of the comedy troupe Porta dos Fundos.

Porta dos Fundos is a Brazilian comedy YouTube channel. It was established in 2012 by Fábio Porchat, Antonio Pedro Tabet, Gregório Duvivier, João Vicente de Castro and Ian SBF in Rio de Janeiro. Its videos often feature closed captions in English. It is owned by Paramount International Networks.