The East Dorset by-election was a Parliamentary by-election. It returned one Member of Parliament to the House of Commons of the United Kingdom, elected by the first past the post voting system.
Hon. Humphrey Sturt had been Conservative MP for the seat of East Dorset since the 1891 By-Election. His succession to the peerage as Baron Alington came on 17 February 1904.
The seat had been Conservative since they gained it in 1886. They held the seat at the last election;
The local Conservative Association selected 47-year-old Charles Van Raalte as their candidate to defend the seat. He was Mayor of Poole in 1903. Van Raalte was of Dutch descent and lived locally on Brownsea Island.
The local Liberal Association selected 29-year-old Hon. Charles Lyell as their candidate to gain the seat. Lyell was commissioned as a lieutenant in the Forfar and Kincardine Artillery Militia in 1900.
Polling Day was fixed for 16 March 1904, 27 days after the previous MP went to the Lord's.
The Liberals gained the seat from the Conservatives;
At the following General Election the result was;