Of Scottish parentage, Anderson was the son of a British Army officer. He was born in Bangalore, South India, and educated at Saint Ronan’s School in Worthing, West Sussex, and at Cheltenham College, where he met his lifelong friend and biographer, the screenwriter and novelist Gavin Lambert; and at Wadham College, Oxford, where he studied English.  After graduating, Anderson worked for the final year of World War II as a cryptographer for the Intelligence Corps, at the Wireless Experimental Centre in Delhi. Anderson assisted in nailing the Red flag to the roof of the Junior Officers mess in Annan Parbat, in August 1945, after the victory of the Labour Party in the general election was confirmed. The colonel did not approve, he recalled a decade later, but no disciplinary action was taken against them.

Before going into film-making, Anderson was a prominent film critic writing for the influential Sequence magazine (1947–52), which he co-founded with Gavin Lambert and Karel Reisz; later writing for the British Film Institute’s journal Sight and Sound and the left-wing political weekly the New Statesman. In a 1956 polemical article, “Stand Up, Stand Up” for Sight and Sound, he attacked contemporary critical practices, in particular the pursuit of objectivity. Taking as an example some comments made by Alistair Cooke in 1935, where Cooke claimed to be without politics as a critic, Anderson responded:

The problems of commitment are directly stated, but only apparently faced. …The denial of the critics moral responsibility is specific; but only at the cost of sacrificing his dignity. … [These assumptions:] the holding of liberal, or humane, values; the proviso that these must not be taken too far; the adoption of a tone which enables the writer to evade through humour [mean] the fundamental issues are balked.”

Following a series of screenings which he and the National Film Theatre programmer Karel Reisz organized for the venue of independently-produced short films by himself and others, he developed a philosophy of cinema which found expression in what became known, by the late-1950s, as the Free Cinema movement. This was the belief that the British cinema must break away from its class-bound attitudes and that non-metropolitan Britain ought to be shown on the nation’s screens.

Along with Karel Reisz, Tony Richardson, and others, he secured funding from a variety of sources (including Ford of Britain) and they each made a series of short documentaries on a variety of subjects. One of Anderson’s early short films, Thursday’s Children (1954), concerning the education of deaf children, made in collaboration with Guy Brenton, a friend from his Oxford days, won an Oscar for Best Documentary Short in 1954.

These films, influenced by one of Anderson’ heroes, the French filmmaker Jean Vigo, and made in the tradition of the British documentaries of Humphrey Jennings, foreshadowed much of the social realism of British cinema that emerged in the next decade, with Reisz’s Saturday Night and Sunday Morning (1960), Richardson’s The Loneliness of the Long Distance Runner (1962) and Anderson’s own This Sporting Life (1963), produced by Reisz. Anderson’s film met with mixed reviews at the time, and was not a commercial success.

Anderson is perhaps best remembered as a filmmaker for his “Mick Travis trilogy”, all of which star Malcolm McDowell as the title character: If…. (1968), a satire on public schools; O Lucky Man! (1973) a Pilgrim’s Progress inspired road movie; and Britannia Hospital (1982), a fantasia taking stylistic influence from the populist wing of British cinema represented by Hammer horror films and Carry On comedies.  In 1981, Anderson played the role of the Master of Caius College at Cambridge University in the film Chariots of Fire.  Anderson developed an acquaintance from 1950 with John Ford, which led to what has come to be regarded as one of the standard books on that director, Anderson’s About John Ford (1983). Based on half a dozen meetings over more than two decades, and a lifetime’s study of the man’s work, the book has been described as “One of the best books published by a film-maker on a film-maker”.

In 1985, producer Martin Lewis invited Anderson to chronicle Wham!’s visit to China, the first-ever visit by Western pop artists, which resulted in Anderson’s film Foreign Skies: Wham! In China. He admitted in his diary on 31 March 1985, to having “no interest in Wham!”, or China, and he was simply “‘doing this for the money'”. In 1986, he was a member of the jury at the 36th Berlin International Film Festival.  Anderson was also a significant British theatre director. He was long associated with London’s Royal Court Theatre, where he was Co-Artistic Director 1969–70, and Associate Artistic Director 1971–75, directing premiere productions of plays by David Storey, among others.

In 1992, as a close friend of actresses Jill Bennett and Rachel Roberts, Anderson included a touching episode in his autobiographical BBC film Is That All There Is?, with a boat trip down the River Thames (several of their professional colleagues and friends aboard) to scatter their ashes on the waters while musician Alan Price sang the song “Is That All There Is?”.  Every year, the International Documentary Festival in Amsterdam (IDFA) gives an acclaimed filmmaker the chance to screen his or her personal Top 10 favorite films. In 2007, Iranian filmmaker Maziar Bahari selected O Dreamland and Every Day Except Christmas (1957), a record of a day in the old Covent Garden market, for his top 10 classics from the history of documentary.