Zi or ZI may refer to:
Arts and entertainment Zi (album), a 2016 album by Negură Bunget Zi (film), a 2026 film by Kogonada Zi (Zoids), a fictional planet in the Zoids franchise
Language Zi (cuneiform), a sign Chinese characters, known as zi (字) Thracian word derived from *Dyēus
People Zi (surname) (子), a surname used by Shang kings Zi (title) (子), a Chinese honorific used for ancient viscounts and for master philosophers Zi (name) (字), an alternate term for East Asian courtesy names
Science, technology and transport Zi Corporation, a Canadian software company Zi (prefix symbol), for digital data size Zona incerta, a brain region Aigle Azur French airline (1946–1955; IATA:ZI)