[3][4][5][6] Son of Lourdes Rosária and Francisco Vieira, Leonardo was born in Belo Horizonte, but grew up in the outskirts of Contagem.

[9] In 2012 he moved to the Eliana Silva Occupation, in the Barreiro [pt] region,[13][14] where he met Poliana Souza, whom he married and has two children.

[7][15][16] From 2014 he served as National President of Popular Unity (UP), which obtained party registration in December 2019 with about 1.2 million signatures.

[12][17] In the 2020 municipal elections, UP considered launching Leonardo as mayor of Belo Horizonte, but chose to run as vice-mayor for candidate Áurea Carolina (PSOL).

[18][19][20][21] At the convention between November 12 and 14, 2021, the party delegates unanimously approved Léo Péricles' pre-candidacy for the Presidency of the Republic in 2022.