Longcross was a British construction company which entered into administration in June 2015. The head office was based in Ashtead, Surrey, England.
The company has undertaken a number of projects for the University of Oxford, including at the Clarendon Laboratory, Denys Wilkinson Building, Mathematical Institute, Merton College, Queen Elizabeth House, Osler House, and a number of other departments. In June 2012, the New Radcliffe House on Walton Street, the new location of the Jericho Health Centre, on the Radcliffe Observatory Quarter development site, was completed by Longcross.
The main page of Longcross's website formerly stated: "We are known for our non-adversarial approach". In 2015, the company went into administration.
From 2012, the Castle Mill site (400m × 25m) between the Cripley Meadow Allotments to the west and the railway tracks by the Castle Mill Stream to the east, north of Oxford railway station on Roger Dudman Way, designed by Frankham Consultancy Group, is being developed as extensive student accommodation for the Oxford University Estates Directorate (OUED) by Longcross. The development has been controversial due to its visibility from Port Meadow, an historic area of undeveloped land to the north. Among other environmental issues, there are badgers on the site.