At the age of 13, Reed began working as an office boy, and at 19 a bank clerk. At the outbreak of the First World War he enlisted in the British Army.He transferred to the Royal Flying Corps, gaining a single kill in aerial combat and severely burning his face in a flying accident. (Insanity Fair, 1938)Around 1921 he began working as a telephonist and clerk for The Times. At the age of 30, he became a sub-editor. In 1927 he became assistant correspondent in Berlin, later transferring to Vienna as chief central European correspondent. He went on to report from various European centres including Warsaw, Moscow, Prague, Athens, Sofia, Bucharest and Budapest.

According to Reed, he resigned his job in protest against the appeasement of Hitler after the Munich Agreement of 1938. But in Somewhere South of Suez: a further survey of the grand design of the Twentieth Century (1949), Reed wrote that his resignation came in response to press censorship which prevented him from fully reporting "the facts about Hitler and National Socialism." He believed that by becoming a "journalist without a newspaper," he would be free to write as he chose. Reed spent the duration of the Second World War in England; in 1948, he moved to Durban, South Africa.

Richard Thurlow noted that Reed was one of the first antisemitic writers to deny Hitler's extermination of the Jews. In a review of Reed's Lest We Regret written in 1943, George Orwell compared Reed's outlook to that of the anti-Hitlerian Nazi dissident Otto Strasser and the British fascist leader Oswald Mosley, stressing Reed's continuing denial of Nazi extermination (as opposed to mere persecution) of the Jews.

In the 1960's Reed was outspoken in his opposition to the decolonization of Africa, considering the Black Africans to be unable to govern themselves and needing prolonged colonial tutelage. In his "The Battle for Rhodesia" (1966) [1] he explicitly compared decolonization to the above-mentioned appeasement of Hitler; he strongly supported Ian Smith's unilateral declaration of independence from the United Kingdom, arguing that Smith's Rhodesia had to be defended as "the last bulwark against the Third World War", just as Czechoslovakia should have been defended against Hitler in 1938.