The magazine was founded in 1974 by Tom Forçade of the Underground Press Syndicate. High Times was originally meant to be a joke: a single-issue lampoon of Playboy, substituting weed for sex. The magazine was at the beginning funded by drug money from the sale of illegal marijuana. But the magazine found an audience, and in November 2009, celebrated its 35th anniversary. Like Playboy, each issue contains a centerfold photo; however, instead of a nude woman, High Times typically features a cannabis plant. The magazine's founding editor was Ed Dwyer (who had earlier written the text of the Woodstock music festival program booklet as well as the Woodstock film program booklet).
The magazine soon became a monthly publication with a growing circulation, audited by ABC as reaching 500,000 copies an issue, rivaling Rolling Stone and National Lampoon. In 2014, its website was read by 500,000 to 5 million users each month. The staff quickly grew to 40 people. In addition to high-quality photography, High Times featured cutting-edge journalism covering a wide range of topics, including politics, activism, drugs, sex, music and film. Tom Forçade was quoted as saying "Those cavemen must've been stoned, no pun intended." Tom Forçade's previous attempts to reach a wide counterculture audience by creating a network of underground papers (Underground Press Syndicate/Alternative Press Syndicate) had failed, even though he had the support of several noteworthy writers, photographers and artists. Yet, through High Times, Forçade was able to get his message to the masses without relying on mainstream media.
In January 2017, the magazine announced it would be relocated to an office in Los Angeles permanently. This followed the legalization of marijuana in several west coasts states, including California. Later in 2017, High Times was acquired by a group of investors led by Oreva Capital.
High Times acquired cannabis media company Green Rush Daily Inc. on April 5, 2018. The deal was valued at $6.9 million. Green Rush Daily founder Scott McGovern joined the magazine as Senior Executive Vice President.