Atheist Community of San Jose is an organization for atheists and like-minded non-believers, founded to develop and support the atheist community and to provide opportunities for socializing, philanthropy, education, and friendship. 

Bay Area Humanists  promote humanism -- an ethical, democratic, naturalistic life stance that prioritizes reason, scientific, and critical thinking -- as well as a system of humanist ethics and secular values as a rational alternative to ethics/values based on religion.

Bay Area Skeptics is one of the SF Bay Area's oldest and longest running science and skepticism organizations, promoting reason and critical thinking through regular meetings, SkepTalks, and social media.

Sacramento Area Skeptics is a nonprofit dedicated to promoting scientific skepticism in our community and around the world.

Wonderfest, the Bay Area Beacon of Science produces in-person and online science programs that stimulate curiosity, promote careful reasoning, challenge unexamined beliefs, and inspire life-long learning.