Ren took gold ahead of teammate Si Yajie, 17, to give China six wins out of seven events in the Olympic diving competition.
Teenager Ren Qian claimed China's sixth diving gold medal of the Rio Olympics by winning the women's 10m platform final on Thursday.
The 15-year-old finished with 439.25 points to beat her compatriot Si Yajie by 19.85 points at the Maria Lenk Aquatics Centre. Canada's Meaghan Benfeito took bronze with 389.20 points.
Ren started inauspiciously before posting scores of 94.05, 91.20 and 91.20 with her final three dives.
China has now won six of the seven diving gold medals decided so far at the Rio Olympics.
The last diving event - the men's 10m platform - will be staged on Saturday.