Mixed is an ethnic group category that was first introduced by the United Kingdom's Office for National Statistics for the 2001 Census.

The Mixed or Multiple ethnic group numbered just under 1.8 million in the 2021 United Kingdom census or 2.7% of the total UK population.

[11] Office for National Statistics estimates suggest that 956,700 mixed-ethnicity people were resident in England (as opposed to the whole of the country) as of mid-2009, compared to 654,000 at mid-2001.

[14] Research conducted by the BBC, however, suggests that the mixed race population could already be twice the official estimate figure - up to 2 million.

[2] The ten local authorities with the largest proportion of those who identified as Mixed were all located in London: Lambeth (8.07%), Lewisham (8.07%), Croydon (7.61%), Islington (7.49%), Southwark (7.20%), Haringey (7.02%), Hackney (6.75%), Hammersmith and Fulham (6.73%), Kensington and Chelsea (6.64%) and Camden (6.63%).