The Henley by-election, 2008 to elect a member of the British House of Commons for the constituency of Henley in Oxfordshire was held on 26 June 2008. It followed the election of Boris Johnson as Mayor of London in May 2008. In order to resign from being an MP, Johnson accepted the post of Steward and Bailiff of the Manor of Northstead on 4 June 2008.
The election was won comfortably by the Conservative candidate John Howell with an increased percentage of the popular vote. The governing Labour Party's vote fell by 11% and they finished fifth, losing their deposit.
Henley was considered a safe seat for the Conservative Party—having been held by the party continuously since 1910 up to this election. Johnson had gained a 12,793 majority from the Liberal Democrats at the previous election, though recent local elections have seen the Liberal Democrats' vote rise. Despite this, an easy win for the Conservative Party candidate was predicted, with the Labour Party being given little to no chance of victory. It had been expected that the by-election would be held after the parliamentary summer recess. However, following their victory in the Crewe and Nantwich by-election, the Conservatives took the opportunity to bring the by-election forward to 26 June, in order to capitalise on their strong support.
Henley by-election may refer to either of three by-elections in the UK parliamentary constituency of Henley;
The Henley by-election, 1932 was a parliamentary by-election held on 25 February 1932 for the British House of Commons constituency of Henley. The seat had become vacant when the Conservative Member of Parliament (MP) Robert Henderson died on 16 January 1932. He had held the seat since the 1924 general election. The Conservative candidate, Sir Gifford Fox, Bt held the seat for the party. He remained the constituency's MP until he retired at the 1950 general election.
The Henley by-election of 1917 was a by-election in Henley caused by the death of Major Valentine Fleming during World War I. The Conservative candidate Robert Hermon-Hodge won the subsequent by-election. He was unopposed due to a War-time electoral pact.