East Dorset is a former United Kingdom Parliamentary constituency. It was formally known as the Eastern Division of Dorset. It was a constituency of the House of Commons of the Parliament of the United Kingdom. It was represented by one Knight of the Shire.

Before 1885 the historic county of Dorset, in south-west England, was an undivided three-seat county constituency - see the article on the Dorset constituency. In 1885 the county was divided for Parliamentary purposes into four single-member county constituencies: this constituency, North Dorset, South Dorset and West Dorset (no borough constituencies were created in Dorset in the 1885 redistribution). Each of these divisions comprised roughly a quarter of the area of the county and returned one Member of Parliament.

In the 1918 redistribution, the four Dorset constituencies were retained, but their boundaries were redrawn. East Dorset was reduced in area to about half its former size, with the northern part of the pre-1918 seat being transferred to North Dorset and the southern part to South Dorset.

In the 1950 redistribution, this constituency disappeared. A new borough constituency of Poole was created. Wimborne Minster Urban District and the part of Wimborne and Cranborne Rural District previously in the abolished seat were transferred to the redrawn North Dorset.

1885–1918: The Municipal Borough of Poole, the Sessional Division of Wimborne, and part of the Sessional Division of Wareham.

1918–1950: The Municipal Borough of Poole, the Urban District of Wimborne Minster, the Rural District of Poole, and part of the Rural District of Wimborne and Cranborne.

• List of former United Kingdom Parliament constituencies