• Arianism, the doctrine propounded by Arius
• Arians or Areians, ancient tribe, living in Aria (satrapy) in western Afghanistan.
• Arian Band, a band
• Polish Brethren, also known as Arians

Arian is also a (near-)homonym of:

• Ariane (rocket), a series of space vehicles
• the French spelling of Ariadne, a character in Greek mythology
• Arrian, Greek historian
• Aryan, a term associated with the Proto-Indo-Irananians
• Aryan race - the racist concept