Viscount Hailsham, of Hailsham in the County of Sussex, is a title in the Peerage of the United Kingdom. It was created in 1929 for the lawyer and Conservative politician Douglas Hogg, 1st Baron Hailsham, who twice served as Lord Chancellor of the United Kingdom. He had already been created Baron Hailsham, of Hailsham in the County of Sussex, in 1928, also in the Peerage of the United Kingdom. Hogg was the son of the merchant and philanthropist Quintin Hogg, seventh son of Sir James Hogg, 1st Baronet, whose eldest son James McGarel-Hogg, 2nd Baronet was created Baron Magheramorne in 1887.
He was succeeded by his son, the second Viscount, who was also a prominent lawyer and Conservative politician. In 1963 he disclaimed his peerages under the Peerage Act 1963, so that he could be elected to the House of Commons. However, in 1970 he accepted a life peerage as Baron Hailsham of St Marylebone, of Herstmonceux in the County of Sussex, and returned to the House of Lords, and like his father served twice as Lord Chancellor of the United Kingdom. The first and second Viscount Hailsham are the only father and son ever to both serve as Lord Chancellor.
On his death in 2001 the life peerage became extinct while he was succeeded in the hereditary barony and viscountcy by his son, the third Viscount. Like his father and grandfather he is a lawyer and Conservative politician and was a Member of Parliament from 1979 to 2010. The House of Lords Act 1999 had by the time of his father's death removed the automatic right of hereditary peers to sit in the House of Lords and he did not need to disclaim his peerages to remain a member of the House of Commons. Lord Hailsham is the husband of Sarah Hogg, Baroness Hogg, a life peeress in her own right.
Viscounts Hailsham (1929) 
- Douglas McGarel Hogg, 1st Viscount Hailsham (1872–1950)
- Quintin McGarel Hogg, 2nd Viscount Hailsham (1907–2001) (disclaimed 1963; created Baron Hailsham of St Marylebone 1970)
- Douglas Martin Hogg, 3rd Viscount Hailsham (born 1945)
The heir apparent is the present holder's son Hon. Quintin John Neil Martin Hogg (born 1973)