Collet Dobson Collet (31 December 1812 – 28 December 1898) was an English radical freethinker, Chartist and campaigner against newspaper taxation.
Collet was born in London on 31 December 1812, the son of John Dobson (1778–1827), a London merchant, and his wife Elizabeth Barker (1787–1875). His sister was the writer and feminist Sophia Dobson Collet (1822–1894). His brother was the engineer Edward Dobson (1816/17?–1908).
After abandoning a career in the law due to lack of money, Collet became director of music at South Place Chapel and was heavily involved in the Chartist movement. He became Secretary of the People's Charter Union, and of the Newspaper Stamp Abolition Committee (i.e. to overturn the Stamp Act) in 1849. From 1851 - 1870 he was Secretary of the Association for the Repeal of the Taxes on Knowledge.
In 1866 he became editor of The Diplomatic Review. This had been known as The Free Press prior to Collet taking it over and was a mouthpiece for the views of David Urquhart. Collet invited radical people to contribute to Diplomatic Review and as a result began publishing articles by Karl Marx. The two became great friends and weekly meetings were held at each other's houses at which Shakespeare readings were given by members of their families. These meetings became formalised as the Dogberry Club. Marx's daughter Eleanor and Collet's daughter Clara, amongst others, became heavily involved in the readings.
His five children included the colonial administrator Wilfred Collet (1856–1929) and the educationalist Clara Collet (1860–1948).