Dian is a given unisex name of:
People:
- Dian Agus Prasetyo (born 1985), Indonesian footballer
- Dian Bachar (born 1970), American actor
- Dian Fossey (1932–1985), American zoologist who studied gorillas
- Dian Genchev (born 1975), Bulgarian footballer
- Dian HP (born 1965), Indonesian composer
- Dian Inggrawati (born 1984), deaf Indonesian beauty queen
- Dian Kateliev (born 1980), Bulgarian footballer
- Li Dian, 3rd century general who served the Chinese warlord Cao Cao
- Dian Moldovanov (born 1985), Bulgarian footballer
- Dian Nissen, American trampolinist, fitness professional, and daughter of the inventor of the trampoline
- Dian Slavens (born 1958), American politician
Mythological or fictional characters:
- Dian Cecht, the god of healing in Irish mythology
- Dian Alberts, on the Dutch soap opera Goede tijden, slechte tijden
- Dian Belmont, a DC Comics character