Opinion polling for the 2005 United Kingdom general election was carried out by various organisations to gauge voting intention. Most of the polling companies listed are members of the British Polling Council (BPC) and abide by its disclosure rules. The opinion polls listed range from the previous election on 7 June 2001 to the election on 5 May 2005.
Poll results are listed in the tables below in reverse chronological order. The highest percentage figure in each poll is displayed in bold, and its background is shaded in the leading party's colour. The "lead" column shows the percentage point difference between the two parties with the highest figures. When a poll result is a tie, the figures with the highest percentages are shaded and displayed in bold.
Most national opinion polls do not cover Northern Ireland, which has different major political parties from the rest of the United Kingdom. The detailed results of parties in the 'others' column can sometimes be found under 'show'.
An exit poll conducted by MORI and NOP for the BBC and ITV was published at the end of voting at 22:00, predicting the number of seats and vote share for each party.
Hartlepool maintained its 2001 boundaries at the 2005 general election.