Garo (ガロ) was a monthly manga anthology magazine in Japan, founded by Katsuichi Nagai [ja] and published by Seirindō [ja; fr] from 1964 until 2002. It was fundamental for the emergence and development of alternative and avant-garde manga.

Katsuichi Nagai founded Garo in July 1964 in order to publish the work of gekiga artists who didn't want to work for mainstream manga magazines after the demise of the rental book industry (kashihon). The magazine offered artists artistic freedom, but didn't pay them any salaries. Nagai particularly wanted to promote Marxist gekiga artist Sanpei Shirato's work, naming the magazine after one of Shirato's ninja characters. The first series published in Garo was Shirato's drama Kamui; exploring themes of class struggle and anti-authoritarianism around a Burakumin ninja boy with an Ainu name. Nagai originally intended the magazine to be for elementary and middle school children to become educated about antimilitarism and direct democracy, publishing essays against the Vietnam War and the rise of the price of school lunch alongside manga. Eventually it became a hit with college students instead. Garo attracted several influential gekiga artists such as Yoshihiro Tatsumi and Yoshiharu Tsuge, and discovered and promoted many new artists.

From 1965 onwards, and especially from 1967 on, the magazine published more and more manga with unconventional form and themes. At the same time, the magazine abandoned its political education project and, while manga published in the magazine stayed critical of militarism and corporate greed, serializations became increasingly "little committed to social change" according to Ryan Holmberg. Garo's circulation at the peak of its popularity in 1971 was over eighty thousand. The magazine was politically affiliated with the Zengakuren and had a big following among the left-wing student movement.

During the 1970s and 1980s its popularity declined. By the mid-1980s its circulation was barely over twenty thousand, and its demise was rumored to be imminent. Nagai managed to keep it going independently until 1991, when it was bought out by a game software company. Although a new, young president was installed and advertisements for computer games (based on stories featured in Garo) started to run in the magazine, Nagai was kept on board as chairman until his death in 1996.

After being bought out by a new owner, there were allegations of the anthology taking a more commercial path. Eventually authors who were regular to Garo went their own ways and founded other anthologies like Ax. Garo ceased publication in 2002.

Over the years, Garo went through many artistic phases, including Shirato's leftist samurai dramas, surreal humour, abstract art and surrealism, erotic-grotesque, and punk.

The magazine's early character was defined not by the grotesque, vulgar, or hyperviolent content often associated with later underground manga anthologies, but by a political and artistic seriousness that drew from Marxist thought, modern Japanese history, and experimental narrative and visual techniques. Important contributors apart from Shirato were Shigeru Mizuki, Yoshiharu Tsuge and Seiichi Hayashi. The early period of the magazine saw manga inspired by "kamishibai paper theatre of the [1940s and 1950s], rental kashihon manga of the late [1950s] and early [1960s], children’s illustrated fiction from the 1930s and [1940s], pre-modern travel literature and Buddhist parables, and Japanese folklore and ghost stories". Ryan Holmberg calls this period traditionalist. Sharon Kinsella writes that the magazine explored "the realm of dreams, collective memories and social psychology" and that its manga were "characterized by obscure and typically nihilistic vignettes about individuals living on the fringes of modern society." She cites Yoshiharu Tsuge's Screw Style as an example.

The magazine was considered too specialist to be clearly identified with one of the four classic manga categorizations shōjo manga, shōnen manga, josei manga, and seinen manga.