The Central Office of Information (COI) was the UK government's marketing and communications service set up in 1946. They took over many of the responsibilities which were previously of the Ministry of Information. The organisation is best known for producing public information films - such as fire safety cartoon Charley Says or the Green Cross Code adverts - but it also appoints advertising agencies and handles media buying on behalf of most government departments.

The COI closed in 2012, with its remaining functions transferred to the Cabinet Office.