John Forster (2 April 1812 – 2 February 1876), was an English biographer and critic and a friend of author Charles Dickens.
He was born at Newcastle upon Tyne. His father, a Unitarian who belonged to the junior branch of a Northumberland family, was a cattle-dealer. Well grounded in classics and mathematics at The Royal Grammar School, Forster was sent in 1828 to the University of Cambridge, but after only a month's residence he moved to London, where he attended classes at University College, and entered the Inner Temple.
His main interests were literary. He contributed to The True Sun, The Morning Chronicle and The Examiner, of which he was literary and dramatic critic; and the influence of his powerful individuality soon made itself felt. Lives of the Statesmen of the Commonwealth (1836–1839) appeared partly in Lardner's Cabinet Cyclopaedia. Forster published the work separately in 1840 with a Treatise on the Popular Progress in English History. It obtained immediate recognition, making Forster a prominent figure in a distinguished circle of literary men which included Leigh Hunt, Edward Bulwer-Lytton, Thomas Noon Talfourd, Albany Fonblanque, Walter Savage Landor, Robert Browning, Thomas Carlyle and Charles Dickens.