Discordianism is a belief system based around Eris, the Greek goddess of strife and discord, and variously defined as a religion, new religious movement, virtual religion, or act of social commentary; though prior to 2005, some sources categorized it as a parody religion. It was founded after the 1963 publication of its holy book, Principia Discordia, written by Greg Hill with Kerry Wendell Thornley, the two working under the pseudonyms Malaclypse the Younger and Omar Khayyam Ravenhurst.

Eris is the Greek goddess of strife and discord. Her Roman equivalent is Discordia, which means the same. Eris's Greek opposite is Harmonia, whose Roman counterpart is Concordia, though she is also described as opposing Nike, counterpart of the Roman Victoria. Homer equated her with the war-goddess Enyo, whose Roman counterpart is Bellona. The dwarf planet Eris is named after the goddess.