Ganyu is a youthful-looking woman with the physical appearance of a late-teenage girl to her early twenties in terms of her appearance (in spite of her actually being thousands of years old). She has long blue hair that fades into a brighter shade at the tips as opposed to the lighter shade it is the closer it gets to her scalp. Her eyes are a mix of pink and purple. Her outfit is a black bodysuit with golden details around her legs underneath. Her sleeves are white with blue at both ends and are detached from her dress, matching her dress' bodice. She has a noticeable pair of black and red horns on her head similar to those of a horn, indicating that she is half-Adeptus.Ganyu is normally quite optimistic and very hardworking. She even outright admits that working is her hobby and her story quest has the employees of Yuehai Pavilion state that she spends her days off thinking about her work. She's easily one of the most reliable people of Liyue as well.

In spite of her generally cheerful nature, Ganyu is actually incredibly insecure about her status as a human-Adeptus hybrid and being accepted into society as a result of it. This is why she generally goes out of her way to hide her Adeptus side from others out of fear of others rejecting or growing afraid of her as a result of it. She is also very conflicted over which side she should live alongside, humanity or Adeptus.Ganyu is also incredibly intelligent, despite being usually rather ditzy and clumsy. This is best shown in her story quest, which had her utilize a social technique she referred to as "your enemy knows you best" to expose a pair of rival merchants, Bolai of Wanyou Boutique and Dongsheng at Second Life, after discovering that had both been evading their taxes as she assisted Huixin in the latter's own work. The trick involved Ganyu tricking Bolai into revealing Dongsheng's abnormal tax reports by stating the Second Life provided large amounts of credit before Ganyu herself then proceeded to investigate the evidence from the carpenter Dongsheng had previously purchased wares from. After she revealed how Bolai had been assisting them in their investigation, Dongsheng admitted Bolai's own acts of tax evasion. Apparently,she learned this trick from Uncle Tian.