Hilary Adair Marquand, PC (24 December 1901 – 6 November 1972) was a British economist and Labour Party politician.

[1] He was born in Cardiff, the son of Alfred Marquand of Saint Peter Port, Guernsey, a clerk in a coal exporting company and his wife Mary née Adair, who was of Scottish ancestry.

[1] He was Director of Industrial Surveys of South Wales, 1931 and 1936, and Member of the Cardiff Advisory Committee Unemployment Assistance Board.

He spent a year in the USA in the study of industrial relations, 1932–1933 and was Visiting Professor of Economics at Wisconsin University in 1938–1939.

[1] Marquand died in 1972 at Hellingly Hospital, East Sussex, aged 70,[1] and was buried at Cathays Cemetery, Cardiff.