Diane Haigh (2 May 1949 – 31 July 2022[2]) was a British architect and faculty member at the University of Cambridge.

She designed the renovation of the Royal Festival Hall in 2007 as well as numerous other refurbishments of historical buildings.

[5] At Allies and Morrison, she led projects including the refurbishment of Queen's House to meet modern accessibility standards (1999), the conversion of Baillie Scott's Blackwell house into an art gallery (2001), and refurbishment of the Royal Observatory's Astronomy Centre (2007) and the Royal Festival Hall (2007).

[2][5] Haigh's work on these historic buildings influenced the guidance of English Heritage—which had previously objected to her proposed designs—on the principles of conservation and restoration.

[2][3] She was appointed a director of design review at the Commission for Architecture and the Built Environment in 2007.