Theta (disambiguation)

Theta may refer to:

• Theta (Greek letter) [r]: The 8th letter of the Greek alphabet, written as $\Theta$ (upper-case) and $\theta$ (lower-case). ^[e]
• Theta function [r]: An analytic function which is a modular form of weight one-half; more generally, the generating function for a quadratic form. ^[e]