The Epsilon Program is a fictional religious cult that is referred to in a number of Grand Theft Auto games in the 3D Universe, and appear in the HD Universe, prominently Grand Theft Auto V. Led by Cris Formage, the cult first emerged as a teaser site for Grand Theft Auto: San Andreas, and more recently a twitter account for GTA V.

The cult is an obvious scam, intended to gain money by brainwashing its followers into paying large sums of money, parodying real-life cults in the late 20th century. In Formage's own words, it is "a fellowship of like-minded adults who tithe money in exchange for salvation and merit badges".

Epsilonism seems to be a parody of Scientology, which is followed by Hollywood celebrities, and is likely to be a central theme to Vinewood celebrities in GTA V.