Neymar, Douglas Costa and teenager Gabriel Jesus will aim to lead their country to its first-ever men's gold medal.
Coach Rogerio Micale's squad also included 37-year-old goalkeeper Fernando Prass, who has never played for his country.
Costa, a winger at Bayern Munich, also figures to play an important role, while Prass was a surprise choice for the third overage player.
Any team would be happy to have a player like him... it will mean a lot for our team."
"I chose him for his leadership profile," Micale explained.
"He is the captain of his team and plays a leading role in the dressing room."
Thiago Silva was again left out of the national team, as were David Luiz and Marcelo.
The under-23 contingent is led by Gabriel Jesus, a 19-year-old striker that is a transfer target for both Real Madrid and Barcelona.
Brazil have won the World Cup five times, but have never won Olympic gold.
The Canarinha have three silver medals (1984, 1988 and 2012) as well as two bronze ones (1996 and 2008).
Full Squad:
Goalkeepers: Fernando Prass (Palmeiras), Uilson (Atletico Mineiro).
Defenders: Luan (Vasco de Gama), Rodrigo Caio (Sao Paulo), Marquinhos (PSG), Douglas Santos (Atletico Mineiro), William (Internacional), Zeca (Santos).
Midfielders: Rafinha (Barcelona), Rodrigo Dourado (Internacional), Fred (Shakhtar Donetsk), Thiago Maia (Santos), Felipe Anderson (Lazio).
Forwards: Neymar (Barcelona), Douglas Costa (Bayern Munich), Gabriel Barbosa (Santos), Gabriel Jesus (Palmeiras) and Luan (Gremio).
