Yu Dong-ju (; born August 19, 1993) is a South Korean male weightlifter, competing in the 85 kg category and representing South Korea at international competitions.
He participated in the men's 85 kg event at the 2015 World Championships and at the 2016 Summer Olympics, finishing in fourteenth position.
In August 2024, Yu Dong-ju competed in the men's 89kg event at the 2024 Summer Olympics held in Paris, France. He lifted 371 kg in total and placed sixth.