The 1887 Dulwich by-election was a by-election held on 30 November 1887 for the British House of Commons constituency of Dulwich in South London.
The by-election was triggered by the appointment of the serving Conservative Party Member of Parliament (MP), John Morgan Howard, as a judge in Cornwall.
The Conservative candidate was John Blundell Maple, who had unsuccessfully contested St Pancras South at the 1885 general election.
The main issue in the by-election was the question of Irish Home Rule, which Henderson, a supporter of Gladstone, supported.
The Liberal Unionists in the constituency supported Maple.