Guilherme Santos Mello, born on June 9, 1983, holds the position of Secretário de Política Econômica (Secretary of Economic Policy) at the Ministério da Fazenda (Ministry of Finance). He has also served as Executive-Secretary of the Ministry.

In addition to his government roles, Mello is a professor at Universidade Estadual De Campinas. He is recognized as a Brazilian economist and sociologist.