Atan may refer to:
Mathematics arctangent (), a trigonometric function atan2, the two-argument function implementing the arctangent in many computer languages
Places Atan, Armenia Atan, Iran
People Atan Shansonga (born 1955), Zambian diplomat Çağdaş Atan (born 1980), Turkish footballer Cem Atan (born 1985), Turkish footballer
See also Attan, a Pashtun and Afghan traditional dance