Etiene Pires de Medeiros (born 24 May 1991) is a Brazilian competitive swimmer who participates in backstroke and freestyle events.

[5] She joined the national delegation which attended the 2011 World Aquatics Championships in Shanghai, China, winning the vacancy after the positive doping of Fabiola Molina.

[11] In January 2013, she moved to São Paulo and started work with Coach Fernando Vanzella in club SESI-SP.

[15] In the final, she finished in 4th place, with a time of 27.83 seconds, her personal best, getting the best placement of a Brazilian woman in the World Championships.

[18] At the 2014 Pan Pacific Swimming Championships in Gold Coast, Queensland, she finished 5th in the 4x100-metre freestyle relay, along with Graciele Herrmann, Daynara de Paula, and Alessandra Marchioro; 5th in the 4x100-metre medley relay, along with Graciele Herrmann, Ana Carla Carvalho and Daynara de Paula; 6th in the 50-metre freestyle; 7th in the 100-metre butterfly; and 11th in the 100-metre backstroke.

On 6 December, in the 4 × 50 metre mixed freestyle relay, Brazil broke the South American record with a time of 1:29.17, only four hundredths slower than Russia, which won the silver medal.

An hour after the unprecedented gold, she won the silver medal in the Women's 50 metre freestyle, with a new South American record, 24.55.

[47] On 13 September 2016, at the José Finkel Trophy (short course competition), she broke the South American record in the 50-metre freestyle with a time of 23.88.

On 11 December 2016, participating in the 2016 FINA World Swimming Championships (25 m) in Windsor, Canada, Medeiros won the gold medal with a time of 25.82, to repeat as the 50m backstroke champion.

In addition to Etiene, the Brazilian team was formed by Felipe Lima, Nicholas Santos, and Larissa Oliveira.

At the 2017 World Aquatics Championships in Budapest, in the Women's 50 metre backstroke, she broke two times the Americas record, with 27.18 in the semifinals, and 27.14 in the final, to obtain her first gold medal.

[58] At the 2019 World Aquatics Championships in Gwangju, South Korea, Medeiros won the silver medal in the Women's 50 metre backstroke.