Kássio Nunes Marques (born 16 May 1972)[1] is a Brazilian magistrate, currently a Justice at the Supreme Federal Court.

On 1 October 2020, president Jair Bolsonaro confirmed the nomination of Nunes to assume a seat in the Supreme Federal Court, due to the retirement of justice Celso de Mello.

[citation needed] On 30 September 2020, president Jair Bolsonaro told the justices of the Supreme Federal Court of his intention to nominate Nunes to be member of the court, replacing justice Celso de Mello, due to his retirement.

His choice was considered, by allies of the president and by the press, as a surprise, given that Nunes wasn't in the lists of potential nominees for the seat.

[9] He is married to Maria do Socorro Marques, who in 2020 worked as a commissioned employee for the staff of senator Elmano Férrer[10] (PODE-PI), and who, previously, served in the staff of senator Wellington Dias (PT-PI) between 2011 and 2014, his first substitute, Regina Sousa (PT-PI), between 2015 and 2018, and second substitute Zé Santana (MDB-PI) in 2019.