Sir John Hobbis Harris (29 July 1874 - 30 April 1940) was an English missionary, campaigner against slavery and Liberal Party politician. He also published a number of books on the subject of slavery between 1910 and 1933. Harris was born in Wantage, Oxfordshire, the son of John Hobbis Harris, a plumber and later a builder. He married Alice Seeley of Frome, Somerset, and together the couple had two sons and two daughters. Harris worked in the City of London for a firm of gentlemen’s outfitters, he was a devout Christian, and undertook evangelical social work before training to become a Protestant missionary in Central Africa. He and his wife Alice departed for the Congo Free State soon after their marriage, but they were horrified by the brutal treatment, murder and enslavement of the native people at the hands of the Belgian agents exploiting the territory for rubber and ivory. In protest, Harris and his wife became active campaigners, bringing the atrocities to the attention of the British government and politicians; they gave evidence at hearings, published books, papers and photographs, gave lectures and addressed hundreds of public meetings. Ahead of his time, Harris became a campaigner against the colonial system of the day and promoted the idea of self-determination for native peoples. From 1910 Harris began organising secretary to the Anti-Slavery and Aborigines Protection Society, an association that led him to take up active politics, culminating in his entry to Parliament at the 1923 general election, when he was elected Liberal Member of Parliament (MP) for North Hackney, defeating the sitting Conservative member Sir Walter Greene. Harris was knighted in the New Year Honours list of 1933 for his services to the Anti-Slavery and Aborigines Protection Society. He died unexpectedly in 1940 in the garden of his home in Frome, Somerset, aged 65 years.