Arthur Meighen, (born June 16, 1874, near Anderson, Ontario, Canada—died August 5, 1960, Toronto), Canadian politician who was Conservative Party leader (1920–26; 1941–42) and prime minister of Canada (1920–21; 1926).

Meighen graduated from the University of Toronto in 1896 and was called to the bar in 1903. In 1908 he was elected to Parliament from Portage la Prairie, Manitoba, where he practiced law. A noted debater, he became solicitor general in 1913 and subsequently held cabinet posts in Robert (later Sir Robert) Borden’s government. When the Conservatives and some Liberals formed a Union Government in 1917, Meighen became minister of the interior. Meighen worked effectively to implement the controversial policies of the Borden government, many of which enlarged Canada’s role in world affairs.

In 1920 Meighen became leader of the Conservative Party and prime minister after Borden resigned the posts. During his first term, Meighen waged a successful campaign in 1921 against renewal of the Anglo-Japanese alliance. Convinced that the chief threat to Canada’s national existence came from the economic power of the United States, he advocated a protective tariff system. A struggling economy and continuing resentment over some of Borden’s policies, however, contributed to the Conservatives’ defeat in the 1921 elections. Meighen became leader of the opposition party, and in 1926 he was asked to form a government following the resignation of W.L. Mackenzie King of the Liberal Party. His second term was cut short by his party’s defeat in the House of Commons and the subsequent general election. Meighen left politics to pursue a career in business but returned in 1932 as minister without portfolio (1932–35) and senator (1932–42). In 1941 he resumed the leadership of the Conservative Party and the following year made an unsuccessful bid for a seat in the House of Commons. He subsequently retired from public life.