He was elected Member of Parliament for Tiverton in 1945 (a constituency previously held by his grandfather Sir John Heathcoat-Amory, 1st Baronet). When the Conservatives came to power under Winston Churchill in 1951 he was appointed Minister of Pensions. In September 1953 he was appointed Minister of State for Trade. He joined Churchill's Cabinet in July 1954 succeeding Sir Thomas Dugdale as Minister of Agriculture and Fisheries (continuing his responsibilities as Minister of State for Trade). In October 1954 these ministries merged under Heathcoat-Amory's leadership. The Hon. Gwilym Lloyd George "later" Viscount Tenby had previously been charged with Food ministerial affairs. He remained in this post until being appointed Chancellor of the Exchequer in 1958, by Harold Macmillan, an office he held until 1960. A highlight of Amory's chancellorship was the raising of Bank Rate to 6% in June 1960, in an effort to cool the economy after the election the previous autumn.