can mean several things:
- Tan (color), the color
- Tangent, a mathematical trigonometric function tan(x)
- Tanning, the process of making leather from hides
- Sun tanning, the darkening of skin in response to ultraviolet light
- Sunless tanning, the darkening of skin without ultraviolet light
- Tan (or Tanfana, Tamfana), ancient European goddess
- Tan (surname) (譚), a Chinese surname - see for examples
- Tan, or Dān (聃), is the posthumous name of Lao Zi (Lao Tzu)
- TAN Books & Publishers, a Catholic publishing company
- OS-tan, an Internet phenomenon on Futaba Channel
- Tahn, a yoghurt-based drink from the Middle East
- Tan (state), ancient Chinese kingdom situated in eastern Shandong Province.
- Tan, Irish slang for an English person, deriving from The Black and 'Tans'
- O-Qua Tangin Wann, Biaviian co-author of the book "The Coming of Tan" (Historicity Productions)
"TAN" or "tan" may also be a three-letter abbreviation for: