Wareham was a parliamentary borough in Dorset, which elected two Members of Parliament (MPs) to the House of Commons from 1302 until 1832, and then one member from 1832 until 1885, when the borough was abolished.

The borough consisted of the town of Wareham on the Isle of Purbeck, a market town close to Poole Harbour. In 1831, the population of the borough was 1,676, and it contained 364 houses.

The right to vote was exercised by the Mayor, magistrates and freemen of the town and all inhabitants paying scot and lot; the number who were qualified to vote under this provision by the time of the Reform Act was unknown, as there had not been a contested election for many years, but there were about 500 in the 1760s. In the early 18th century a number of wealthy local families were influential over the choice of members, but eventually John Calcraft of Kingstone Hall secured total control by buying up all the property in the borough occupied by potential voters.^[1]

Wareham retained one of its two MPs under the Reform Act, but its boundaries were extended to include several surrounding areas, including nearby Corfe Castle which had previously been a borough in its own right. The new borough had a population of 5,751.

The borough continued to elect one MP until the third Reform Act, which came into effect at the general election of 1885. This abolished the constituency, Wareham being placed in the new East Dorset county division.