Doncaster (/ˈdɒŋkəstər/, /-kæs-/) is a city in South Yorkshire, England. Named after the River Don, it is the administrative centre of the larger City of Doncaster. It is the second largest settlement in South Yorkshire after Sheffield. Doncaster is situated in the Don Valley on the western edge of the Humberhead Levels and east of the Pennines. At the 2021 census, the city had a population of 308,100, while its built-up area had a population of 158,141 at the 2011 census.