Educated in the traditional way, at Eton College and Christ Church, Oxford, and embarked on an academic career, becoming a Fellow of All Souls in 1931. He had trained in law, and was called to the bar in 1932. From there it was a short step into politics, and he followed his father's example, becoming MP for Oxford in 1938 and holding the constituency until 1950. At this point, his father died, and he was obliged to give up the House of Commons to become 2nd Viscount Hailsham. He continued as a leading member of the Conservative party, becoming First Lord of the Admiralty in 1956, and held a number of ministerial posts in the years prior to the crisis of 1963 which forced the then prime minister, Harold Macmillan, to resign.
In November, 1963, Hailsham took advantage of recent changes in the law to renounce his peerage in order to contest the leadership of the party, and became once more an MP, this time for St Marylebone, a London constituency. Having failed to win the leadership of the party, which eventually went to Edward Heath, he continued in ministerial office until 1970, when he became Lord Chancellor in Heath's government. He held the same post from 1979 to 1987 under Margaret Thatcher. Although Hailsham's ability was great, he was an old-school Tory whose bumbling upper-class style did not appeal to the public.
The highest office he reached, that of Lord Chancellor, is the only office in the British cabinet which actually requires the holder to be a peer, and he was made a life peer as Lord Hailsham of St Marylebone specifically for the purpose of allowing him to hold the said post. He thus became the second person (after Alec Douglas-Home) to become a life peer after renouncing a hereditary peerage.
On his death the viscountcy was inherited by his son Douglas Hogg MP. As a result of the House of Lords Act 1999, which removed the automatic link between peerages and the right to sit in the House of Lords, the 3rd Viscount has not had to disclaim the title in order to continue to sit as an MP.