It is, with 194,394 people according to Office of National Statistics estimate for mid 2022, the most populous district in Essex and also includes the towns of West Mersea and Wivenhoe and the surrounding rural areas stretching from Dedham Vale on the Suffolk border in the north to Mersea Island in the Colne Estuary in the south.

Colchester was an ancient borough with urban forms of local government from Saxon times.

[6] As part of the Platinum Jubilee of Elizabeth II celebrations in 2022, the borough of Colchester was granted city status, confirmed by Letters Patent dated 5 September 2022, allowing the council to change its name to "Colchester City Council".

Parts of the district are also covered by civil parishes, which form a third tier of local government.

Political control of the council since 1974 has been as follows:[12][13][14] The role of mayor is largely ceremonial in Colchester.

[19] Based on ethnic groups, predominantly of 92% of the population is White (87.5% British, 0.7% Irish and 3.8% Other White), Asians were the second largest making up 3.6% (0.8% Indian, 0.2% Pakistani, 0.2% Bangladeshi and 1% Chinese, other 1.4%), Black people constituted 1.4% (0.3% Caribbean, 1% African, 0.1% other), those of mixed race made up 1.8%, 0.6% were Arab and there were 0.4% from other ethnic groups.

Of other religions, 1.6% identified as Muslim, 0.7% Hindu, 0.6% Buddhist, 0.2% Jewish, 0.1% Sikh, 0.5% others, and 7.3% did not answer.