Woodcock was born in Winnipeg, but moved with his parents to England at an early age. The family was quite poor, but Woodcock had the opportunity to go to university in Oxford on a scholarship. However, he turned down the chance, because he would have had to have joined the clergy.
Instead, he took at job as a clerk at the Great Western Railway, and it was while there that he first became interested in anarchism (specifically libertarian socialism). He was to remain an anarchist for the rest of his life, writing several books on the subject, including the aforementioned Anarchism, The Anarchist Reader (an anthology edited by him; 1977) and biographies of Pierre-Joseph Proudhon and Peter Kropotkin.
Also around this time, he met several prominent literary figures, including T. S. Eliot and Aldous Huxley. He first came to know George Orwell after the two of them had a public disagreement in the pages of the Partisan Review when Orwell wrote that pacifism was "objectively pro-Fascist". As a pacifist himself, Woodcock took exception to this. However, the two met and became good friends, with Woodcock later writing The Crystal Spirit, a biography of Orwell which won a Governor General's Award in 1966
Woodcock spent World War II working on a farm. Following the war, he moved to Canada and settled in Vancouver. In 1955, he took a post in the English department of the University of British Columbia, where he stayed until the 1970s. Around this time he started to write more prolifically, producing several travel books and collections of poetry, as well as the works on anarchism for which he is best known.
Towards the end of his life, Woodcock became increasingly interested in what he saw as the plight of Tibetans. He travelled to India, studied Buddhism, became friends with the Dalai Lama and established the Tibetan Refugee Aid Society.
Woodcock was honoured with several awards, including a Fellowship of the Royal Society of Canada in 1968, the UBC Medal for Popular Biography in 1973 and 1976 and the Molson Prize in 1973. However, he only accepted awards given by his peers, refusing several awards given by the Canadian government, including the Order of Canada. The one exception to this was the award of the Freedom of the City of Vancouver, which he accepted in 1994.