McNeil was born in Garelochhead and educated at Woodside School and the University of Glasgow, trained as an engineer and worked as a journalist on a Scottish national newspaper.

[1] Through his position at the Foreign Office, he was vice-president of the United Nations General Assembly in 1947 and leader of the British delegation to the Economic Commission for Europe, 1948.

It was later revealed that his personal assistant and private secretary at the time, Guy Burgess, was a Soviet agent, although McNeil never came under suspicion.

[1] In the last years of his life, he served as managing director of Encyclopædia Britannica, Inc.[1] In 1955, when travelling to New York City for business on the RMS Queen Mary, he suffered a cerebral haemorrhage; upon arriving in New York on 3 October, he was taken to Columbia Presbyterian Medical Center, where he died on 11 October, aged 48.

[5] In May 2014, Inverclyde Council approved the name Hector McNeil House for the former library building in Clyde Square, Greenock when it re-opened as the main offices for Community Health and Care Partnership services in August 2014.