Leonardo de Deus

2010–12

In 2010, Deus joined the Brazilian national delegation and participated in the 2010 South American Games in Medellin. He won two gold medals, in the 200-metre backstroke and in the 200-metre butterfly, and a silver in the 4x200 freestyle relay.

He competed in the 2010 Pan Pacific Swimming Championships in Irvine, where he finished 9th in the 200-metre butterfly, and 11th in the 200-metre backstroke.

He also participated in the 2010 FINA World Swimming Championships (25 m), in Dubai, where he finished 28th in the 100-metre backstroke and 15th in the 200-metre butterfly.

He qualified for the semifinals of the 200-metre butterfly with the second fastest time (1:55.55) at the 2011 World Aquatics Championships in Shanghai, finishing 13th in the semifinal. He also qualified for semifinals of the 200-metre backstroke, finishing 15th.

Deus was at the 2011 Pan American Games in Guadalajara, where he was crowned champion of the 200-metre butterfly, after a controversy involving alleged irregular sponsorship in the cap used in the final. Leonardo was disqualified after the game, but after protests from fans and the athletes themselves, the gold medal was returned to him. He also won silver in the 4×200-metre freestyle.

2012 Summer Olympics

At the 2012 Summer Olympics, he qualified for the semifinal of the Men's 200-metre backstroke, finishing in 16th place overall in the heats, and seventh in his semifinal, failing to qualify for the final. He finished 13th in the 200-metre backstroke. He also came in 21st place in the 200-metre butterfly.

2013–16

At the 2013 World Aquatics Championships in Barcelona, Deus finished in 7th place of his first classification to a World Championship final, the 200-metre butterfly final, with a time of 1:56.06. He participated in the 200-metre backstroke, finishing 12th. He also participated in the 4×100-metre medley, finishing 12th, along with Marcelo Chierighini, Felipe Lima and Nicholas Santos.

At the 2014 South American Games in Santiago, Chile, he won two gold medals in the 200-metre butterfly and 200-metre backstroke, breaking the competition record in both races.

At the 2014 Maria Lenk Trophy in São Paulo, Deus broke the Brazilian record in 400-metre freestyle with a time of 3:50.90, improving Armando Negreiros's time from 1997 by twenty-eight hundredths of a second. In May 2014, at the Brazilian Junior and Senior Swimming Championships, he broke the Brazilian record again with a time of 3:50.71.

At the 2014 Pan Pacific Swimming Championships in Gold Coast, Queensland, Australia, he won a silver medal in the 200-metre butterfly, with a time of 1:55.28. He also finished 6th in the 200-metre backstroke and 12th in the 400-metre freestyle heats.

At the Brazilian Open, in Rio de Janeiro, he broke, for the third time, the Brazilian record in the 400-metre freestyle, with a time of 3:50.37.

In April 2015, at the Maria Lenk Trophy, in Rio de Janeiro, he broke the South American record in the 400-metre freestyle, with a time of 3:49.62, and swam lifetime best in the 200-metre butterfly, with a time of 1:55.19, earning the best time of the year in the event.

At the 2015 Pan American Games in Toronto, Canada, de Deus won three medals: a gold in the Men's 200 metre butterfly, with a time of 1:55.01, new Pan Am Games record and a lifetime best; and two bronze medals in the Men's 200 metre backstroke and in the Men's 400 metre freestyle.

At the 2015 World Aquatics Championships in Kazan, de Deus din't swim well in the Men's 200 metre butterfly. In the semifinal, he finished with a time of 1:56.02, far from his best mark, 1:55.01 achieved in Pan American Games few days ago, and finished in 9th place, losing a spot in the final by 0.28 seconds. He also finished 13th in the Men's 200 metre backstroke.

2016 Summer Olympics

At the 2016 Summer Olympics, he broke the Brazilian record in the Men's 200-metre backstroke, with a time of 1:57.00, at heats. He finished 13th place overall in the semifinals. In the Men's 200 metre butterfly, he didn't swim well: although he had earlier times that could qualify him for the Olympic final, didn't come close to these times, and with the 1:56.77 mark, he finished 13th place in the semfinals.

2016–20

At the 2016 FINA World Swimming Championships (25 m) in Windsor, Ontario, Canada, he went to the Men's 200 metre butterfly final, finishing 5th. He also finished 11th in the Men's 200 metre backstroke

At the 2017 World Aquatics Championships in Budapest, he finished 12th in the Men's 200 metre backstroke and 14th in the Men's 200 metre butterfly.