Denis Vieru (born 10 March 1996) is a Moldovan judoka who competes in the men's half-lightweight (66 kg) category.

Vieru rose to prominence after winning a gold medal at the 2016 European U23 Championships, the first Moldovan to do so since Marcel Trudov in 2005.

[4] He also defeated Ranto Katsura of Japan to win a gold medal at the 2019 Summer Universiade in Naples, where he was the flag bearer for the Moldovan delegation in the opening ceremony,[5] and later also won a bronze medal at the 2019 World Championships.

[6] Vieru's medal as well as his points from the 2019 summer's competitions were suspended for a while, while the Moldovan was investigated for use of doping.

[10] Vieru became the 2023 European champion and as of May 2024 is also the world's top ranked judoka in his weight class (66 kg).