Born in the City of Westminster, Lord Wolmer was the eldest son of the 2nd Earl of Selborne and his wife, the former Lady Beatrix Cecil, a daughter of the 3rd Marquess of Salisbury. He was educated at Winchester College and graduated from University College, Oxford in 1909. On 9 June 1910, he married the Hon. Grace Ridley (the third daughter of the 1st Viscount Ridley) and they had six surviving children:
A few months later, at the December 1910 general election Lord Wolmer entered Parliament as MP for the Newton constituency in Lancashire. He was Parliamentary Private Secretary to his uncle, the Under-Secretary of State for Foreign Affairs, Lord Robert Cecil in 1916 and Assistant Director of the War Trade Department from 1916-18. At the 1918 general election, he did not stand in Newton (which was won by the Labour Party politician, Robert Young), but was elected to the newly-formed constituency of Aldershot that year. From 1922-24, he was Parliamentary Secretary to the Board of Trade and Assistant Postmaster-General from 1924-29.
In 1940, Lord Wolmer left the Commons when he was called up the House of Lords in his father's barony of Selborne and was Director of Cement at the Ministry of Works from 1940-42. In 1942, he inherited his father's earldom and his last political post was as Minister of Economic Warfare from 1942-45. This put him in charge of the Special Operations Executive, which ran undercover operations of sabotage in Occuppied Europe. He was made a member of the Order of the Companions of Honour after the war and in 1948 was Master of the Worshipful Company of Mercers, then chairman of the National Provincial Bank from 1951-53 and deputy chairman of Boots from 1951-64.
Lord Selborne's wife died in 1959 and on 3 March 1966, he married Valerie Bevan née de Thomkahaza, a daughter of a Hungarian politician. His eldest son had also died on active service in 1942 and upon his own death in 1971 in Alton, Hampshire aged 84, was succeeded in his titles by his grandson, John.