Iain Macleod (1913 – 1970) was a UK Conservative politician.

He represented the parliamentary constituency of Enfield, West, and served as a minister in the Conservative Governments of the 1950s. As Minister for Health under Winston Churchill (after succeeding Henry Crookshanks to the post in 1952) he famously made the announcement that British clinician Richard Doll had proved the link between smoking and lung cancer at a press conference during which he chain smoked throughout.

In the Macmillan governments he served as first Minister of Labour and National Service (1957-9) and then as Secretary of State for the Colonies (1959-61) where he presided over considerable decolonisation; in 1961 he added the Chancellorship of the Duchy of Lancaster to his portfolio.

But when Harold Macmillan acted to block the succession of Rab Butler to his position as Conservative party leader and prime minister, Macleod (along with Enoch Powell) refused to serve under Alec Douglas-Home and was subsequently passed over for a position in the Douglas-Home government.

He was at one time editor of The Spectator, and the coinage of the word stagflation is attributed to him.

Shortly before his death he had been appointed as Chancellor of the Exchequer by Prime Minister Edward Heath. He left behind him an outline budget which most observers found surprisingly hard-line in its proposals for control of public spending and tax reform.

Many conservative politicians of generations following Macleod recalled him as an inspirational speaker, and John Major specifically cited his example on taking office. Many believe he would have made a good leader for the party had he lived.