Thiago Pereira is a swimmer who has competed for Brazil.
He competed at the 2004, 2008, 2012, and 2016 Summer Olympic Games. He won a silver medal in the 400 metres individual medley at London 2012, surpassing the defending champion Michael Phelps by 0.32 of a second but finishing behind the winner Ryan Lochte by a wide margin of three seconds. He was also one of the swimmers, along with Phelps and Lochte, to enter the final of the 200 metres individual medley four times.