Holland, Hannen & Cubitts was a major building firm responsible for many of the great buildings of London.

The company was formed from the fusion of two well-established building houses that had competed throughout the later decades of the nineteenth century but came together in 1883: this was implemented by Holland & Hannen acquiring Cubitts, a business founded by Thomas Cubitt some 70 years before.^[1] During the Second World War the company was one of the contractors engaged in building the Mulberry harbour units.^[2]

In the 1960s, when Lord Ashcombe was the Chairman of the company, it held a major stake in ACI Property Corporation, the developer for the Le Cartier Apartments in Montreal.^[3]

The company was acquired by Drake & Gorham Scull^[1] in 1969 and then by Tarmac in 1976 and subsequently integrated into Tarmac Construction.^[4]

The combined business went on to construct many important buildings and structures including the Holborn Bars in High Holborn completed in 1906,^[5] the Cunard Building in Liverpool completed in 1917,^[6] the Cenotaph in London completed in 1920,^[7] County Hall, London completed in 1922,^[8] Ironmongers' Hall completed in 1925,^[1] Unilever House completed in 1930,^[9] South Africa House in London completed in 1933,^[1] the Senate building of the University of London completed in 1937,^[1] the Royal Festival Hall in London completed in 1951,^[1] the Roxburgh Dam in New Zealand completed in 1956,^[1] New Zealand House in London completed in 1961,^[1] the West London Air Terminal completed in 1963,^[10] and Trawsfynydd nuclear power station completed in 1965.^[1]