Ian is a common given name, the Scottish Gaelic version of the name John.

Ian or IAN may also refer to:

• Inferior alveolar nerve, in biology
• International Article Number
• Internet area network
• IATA airport code for Bob Baker Memorial Airport, Kiana, Alaska

• "Ian", a song by White Town from Socialism, Sexism & Sexuality
• Ian., the abbreviation of the month of January in the Roman calendar
• ian (rapper), American rapper, songwriter and record producer
• List of storms named Ian
• Mount Ian, a mountain in New Zealand

• IANS (disambiguation)