The first population count in Sierra Leone was undertaken in 1802 in what is now the Western Area. However, the first modern population census to cover the whole country, was conducted in April 1963. Since then, four more censuses have been undertaken in December 1974, December 1985, December 2004 and December 2015 respectively. It is worth noting that because of the difference in the methodology used in the censuses prior to 1963, the population totals of the country prior to 1963 cannot be compared with those of recent censuses.
Due to the improvement of the census methodology in the 1963 population census, a reliable and trustworthy population figure of 2,180,355 was accepted for informed consent and further improvement on the other censuses continued.
The 2004 Census collected information on many demographic and socio-economic characteristics and recorded a total population of 4,976,871 persons, with a sex ratio of 94. Its preliminary report was published in February 2005 and the analytical report finalized in July 2006. Following the decennial census programme, the next census was expected in December 2014. However, following the spread of the Ebola epidemic from Guinea and Liberia to Sierra Leone, with the first case recorded in May 2014 in Kailahun District, a recommendation was made by Statistics Sierra Leone (SSL) to the Government of Sierra Leone that the main field enumeration should be shifted from December 2014 to April 2015. But as the epidemic intensified, it was further postponed to December 2015. The Government of Sierra Leone accepted and announced both postponements.
The population of Sierra Leone has grown from 2,180,355 in 1963 to 2,735,159 in 1974, 4,976,871 and 7,092,113 in 2004 and 2015 respectively.