A borough constituency is, in the United Kingdom, a Parliamentary constituency that is predominantly urban and thus designated to be a borough constituency. Borough constituencies are the successors to the historic parliamentary boroughs. There are some technical election-law related differences between borough and county constituencies governing the maxmum amount a candidate can spend, with lower limits for borough constituencies than for counties as it recognises that a more compact electorate requires fewer costs than a geographically spread out one.

Sometimes a town can be covered by more than one constituency, with one a borough and another a county. Reading and Milton Keynes are both examples of this.