Oz was an independently published, alternative/underground magazine associated with the international counterculture of the 1960s. While it was first published in Sydney in 1963, a parallel version of Oz was published in London from 1967. The Australian magazine was published until 1969 and the British version until 1973.

The terms underground press or clandestine press refer to periodicals and publications that are produced without official approval, illegally or against the wishes of a dominant group. In specific recent Asian, American and Western European context, the term "underground press" has most frequently been employed to refer to the independently published and distributed underground papers associated with the counterculture of the late 1960s and early 1970s in India and Bangladesh in Asia, in the United States and Canada in North America, and the United Kingdom and other western nations. It can also refer to the newspapers produced independently in repressive regimes. In German occupied Europe, for example, a thriving underground press operated, usually in association with the Resistance. Other notable examples include the samizdat and bibuła, which operated in the Soviet Union and Poland respectively, during the Cold War.