Aliksei Uladzimiravich Mzhachyk (; 30 June 1996 â 1 August 2021) was a Belarusian weightlifter. He placed 12th in the men's +105 kg event at the 2016 Summer Olympics held in Rio de Janeiro, Brazil.
In age-specific categories he won the bronze medal at the 2017 European Junior & U23 Weightlifting Championships. He finished eighth at the 2017 European Weightlifting Championships and thirteenth at the 2018 World Weightlifting Championships.
Mzhachyk died in a car accident in Germany on 1 August 2021. He was 25.