Logica is a global IT and management consultancy company headquartered in Reading, United Kingdom.

It has a primary listing on the London Stock Exchange and is a constituent of the FTSE 250 Index. It has a secondary listing on Euronext Amsterdam.

On 31 May 2012 Canada's CGI Group agreed to acquire Logica in a £1.7bn cash deal.

Logica was founded by Len Taylor, Philip Hughes and Pat Coen as a systems integration business in 1969. Early projects included the control system for the natural gas grid in the UK in 1971 and the design of the SWIFT network for international money transfers in 1973.

In 1974, Logica, together with the French company SESA, set up a joint venture, Sesa-Logica, to undertake the European Informatics Network development. This project, undertaken with the support of partners throughout Europe and with the assistance of Bolt, Beranek and Newman in Cambridge, Massachusetts, brought the core datagram technology of the Arpanet, now the Internet, to Europe for the first time, and established a network linking research centres in a number of European Countries, including CERN, the French research centre INRIA and the UK’s National Physical Laboratory.