This article is an introduction to the special issue “Atheism, Agnosticism, and Nonreligious Worldviews.” The articles in the special issue highlight starting points and paths for continued growth in developing methodologies and theories that will allow atheists and the nonreligious to be understood apart from, yet compared with, their religious counterparts. (PsycINFO Database Record (c) 2018 APA, all rights reserved)