The 1861 census of the United Kingdom is taken

Background. National decennial censuses of the general population began in 1801, championed by statistician John Rickman. These censuses were initially conducted to ascertain men able to fight in the Napoleonic Wars and address population concerns from Malthus's work. Coincident full censuses have taken place in UK jurisdictions every ten years since 1801, with specific exceptions.

Administration. National censuses in Scotland have been taken on the same dates as those in England and Wales, but with differing legislation, governorship, and archiving arrangements. The General Register Office for Scotland has been described as responsible for taking the census in Scotland since 1861; the supplied passages do not detail the specific administration of the 1861 census itself.

Format. The 1861 census recorded people residing in every household on the night of 7 April 1861. It was the third UK census to include details of household members. The format was identical to the previous 1851 census, despite pressures for 'religious affiliation' questions to be included.