A series of book-sized journals created by Aleister Crowley. The ten issues of the first volume appeared on the equinoxes between 1909 and 1913. Volume II was never published. The first issue of volume III was published in 1919 and was known as the “Blue Equinox” due to the color of the cover. The second issue of the volume was not published. Crowley published issues 3–5 between 1939 and 1944. Other issues and volumes have been published after Crowley's death by people representing—or claiming to represent—Crowley’s legacy.

Controversy began with the first issue as it revealed some of the secrets of the Hermetic Order of the Golden Dawn. The Order’s head, MacGregor Mathers, filed a lawsuit to halt publication, but lost. (Curiously, Israel Regardie was attacked by members of the Golden Dawn for publishing material about the Order in the volumes of his book, The Golden Dawn, even though Crowley had published much of the same material almost 30 years earlier.)

The articles in "The Equinox" comprise one of the most complete explications of the Western occult tradition and magick ever published, combined with poetry, book reviews, and even personal attacks. In 1974, Israel Regardie published only the magical information from the ten numbers of volume I and the "Blue Equinox" in Gems from The Equinox (originally from Llewellyn Publications, now from New Falcon Publications).