Rev Sir Herbert Dunnico (2 December 1875 – 2 October 1953) was a British Baptist minister, leading Freemason and Labour Party politician.
Born in Wales, he started work in a factory aged ten, but studied in his spare time and won a scholarship to University College Nottingham. He was ordained as a Baptist minister in Warrington and Liverpool, and became president of the Liverpool Free Church Council.
He formed the Peace Negotiation Committee in 1916 to call for a truce with Germany.
A committed socialist, he was elected at the 1922 general election as Member of Parliament (MP) for Consett. From 1929 to 1931 he was Deputy Speaker of the House of Commons, and Chairman of the Ways and Means Committee.
Dunnico also holds the distinction of being the Labour Party's first backbench rebel, when on 21 February 1924 he became the first Labour MP ever to vote against a Labour government. The vote was on the First Labour Government's programme of building light cruisers, to which Dunnico (a former secretary of the Peace Society) objected because he feared the start of an arms race, and because believed that the Parliamentary Labour Party had not been properly consulted.
At the 1931 general election, he was defeated in Consett by the Liberal National candidate John Dickie. In January 1935 Dunnico announced that he felt it his duty to support the National Government because he felt political partisanship was damaging to the national interest. He was National Labour candidate at Wednesbury at the 1935 general election but narrowly failed to win election.