Though planning for a career in the law and in politics, he undertook freelance editing work for The Times while reading for the Bar, and in February 1914 was given a position as secretary to the editor, Geoffrey Dawson.
While he was called to the Bar at Lincoln's Inn a few weeks after the end of the war, early in 1919 he received an invitation to become an assistant editor of a Sunday newspaper The Observer.
The position provided Barrington-Ward with valuable experience in the management and operations of a newspaper, and he developed a close friendship with the legendary editor.
His responsibilities soon grew: in 1929, he began writing most of the leading articles on domestic policy and European matters, and in 1934 he was made deputy editor.
Lester B. Pearson, then a young chargé d'affaires in the Canadian High Commission, recalls in his memoirs a visit paid by Barrington-Ward in furtherance of the appeasement policy which was fashionable in that era:[4] There now followed another Nazi violation of the Treaty of Versailles, the reoccupation of the Rhineland in March 1936.
I agreed with the London Times as it thundered against strong anti-Nazi policy and emphasized the danger of precipitate action against a Germany which, however deplorable its regime, was trying merely to free itself from some of the worst shackles of an unjust treaty...
Though Barrington-Ward accepted, Dawson's departure was conditional on the continuance of peace, and the outbreak of war led him to postpone his retirement indefinitely.
In terms of the war, Barrington-Ward believed that it was generally the patriotic duty of the paper to support the government, he reserved the right to oppose specific policies, such as the deployment of British troops to Greece in 1944.