Thiago Machado Vilela Pereira (born 26 January 1986) is a retired Brazilian international competition swimmer.

Pereira is a resident of Belo Horizonte, and became known as Ricardo Prado's successor in his native country after winning the silver medal in the 200-meter individual medley at the Pan American Games in Santo Domingo, Dominican Republic in 2003.

[1] After several more competition wins between the ages of 13 and 16, Pereira received a proposal to join Belo Horizonte's Minas Tênis Clube in 2001, under the command of coach Fernando Vanzela.

He moved to Coral Springs, Florida, but could not adapt to the local environment, methods and customs, and returned to Belo Horizonte.

[1] In August 2011, he accepted a proposal to integrate into César Cielo's project PRO 16, under the command of Brazil's national swimming team coach Albertinho Silva.

[1] In December that year, he announced that would stay in Brazil full-time, living in São Paulo to train with Silva.

[18] In May 2004, Pereira broke Ricardo Prado's long-course South American record in the 400-meter individual medley, made at the 1984 Summer Olympics, which had been 4:18.45.

[25] At the 2004 FINA World Swimming Championships (25 m) in Indianapolis, Pereira won the gold medal in the 200-meter individual medley with a time of 1:55.78, defeating Ryan Lochte[26] and breaking the South American record.

[31] In May 2005, Pereira dislocated the kneecap while playing soccer; his recovery took two months and did not participate in the 2005 World Aquatics Championships in Montreal.

[32] At the 2005–2006 FINA Swimming World Cup in February 2006, Pereira broke the short-course South American record in the 100-meter individual medley with a time of 53.49 seconds.

[33] At the 2006 FINA World Swimming Championships (25 m) in Shanghai, Pereira finished 5th in the 4×200-meter freestyle[34] with teammates César Cielo, Lucas Salatta and Rodrigo Castro, beating the South American record with a time of 7:06.09.

[37] At the 2006 Pan Pacific Swimming Championships in Victoria, British Columbia, Pereira won a bronze medal in the 400-meter individual medley.

[42] In December 2006 at the Pan Pacific Swimming Championships, he beat his South American record by more than two seconds in the 400-meter individual medley with a time of 4:14.67.

[49] He broke the South American record in the 4×100-meter freestyle along with César Cielo, Nicolas Oliveira and Rodrigo Castro, with a time of 3:17.03.

[51] Pereira broke the South American record in the 200-meter individual medley three in three months with times of 1:59.19 in February, 1:58.65 in March (Melbourne heats) and 1:58.64 in May.

[59][60][61][62] In the 200-meter individual medley, Pereira won a gold medal with a time of 1:53.14, establishing a new World Record that stood until 13 December 2007.

[64] But in the final, his time was 4 seconds slower; Pereira said that he felt tired in the change from the butterfly to the backstroke, not achieving the same efficiency as in the heats.

[66] In the 200-meter individual medley, he had very similar results in the heats, semifinals and finals, all near 1:58—failing to beat his record from the 2007 Pan American Games.

[67] In March 2009, Pereira broke a bone in his left hand, which made him give up Travessia dos Fortes and compromised his training for that year's World Championships in Rome.

[94] At the 2012 Summer Olympics in London, Pereira won the silver medal in the 400-meter individual medley, defeating Michael Phelps.

[95][96] In the 200-meter individual medley, although he made his best-ever time without technological suits (1:56.74), Pereira was beaten in the last 25 meters by Hungarian László Cseh.

[97] In August 2012, at the Jose Finkel Trophy, he broke the short-course South American record in the 200-meter individual medley, with a time of 1:52.30.

[105] He won a gold medal in the 4×200-metre freestyle relay, where he broke the Pan Am Games record with a time of 7:11.15, along with Luiz Altamir Melo, Nicolas Oliveira and João de Lucca.

[106] In the 400 metre individual medley, Thiago Pereira initially won, which would make it his third consecutive title along with a record 22nd Pan American medal.

[113][114] He also finished 15th in the Men's 4 × 200 metre freestyle relay, along with João de Lucca, Luiz Altamir Melo and Nicolas Oliveira.