The 1910 East Dorset by-election was a Parliamentary by-election held on 30 June 1910. The constituency returned one Member of Parliament (MP) to the House of Commons of the United Kingdom, elected by the first past the post voting system.

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.