In 1901, Birbhum had a population of 902,280, which by 1981 rose to 2,095,829. According to the 2001 census data, the total population has further risen to 3,015,422. The following table summarises the population distribution:
{| class="wikitable"
|-
! Rural/Urban
! Persons
! Males
! Females
|-
| Total
| 3,015,422
| 1,546,633
| 1,468,789
|-
| Rural
| 2,757,002
| 1,414,097
| 1,342,905
|-
| Urban
|258,420
|132,536
|125,884
|}
According to the 2011 census Birbhum district has a population of 3,502,404, roughly equal to the nation of Lithuania or the US state of Connecticut. This gives it a ranking of 84th in India (out of a total of 640). Other than those speaking the local dialect of Bengali, there are tribal Santhals and ten other tribal communities in Birbhum with some presence, amongst whom Koda, Mahali and Oraons are more common.