Privately owned multinational construction and engineering group founded in 1978 by Ray O'Rourke as R. O'Rourke & Son, headquartered in Dartford.

Laing O’Rourke was founded in 1978 by Ray O’Rourke and his brother Des as R. O’Rourke & Son, initially a concrete subcontractor based in East London. It took its current name in September 2001 after buying main contractor Laing Construction from John Laing plc for £1, and acquired Crown House Engineering in 2004. It is headquartered in Dartford, Kent, and is described as the largest privately owned construction company in the United Kingdom, with Ray O’Rourke as chairman and Cathal O’Rourke as chief operating officer.