Samuel Clapham (1755–1830) was a clergyman of the Church of England, a justice of the peace, and a writer.
His best known work, the collection Practical Sermons on Several Important Subjects, published under the pseudonym Theophilus St. John, went through four editions (1803, 1804, 1808, 1812).
One of these, How far Methodism conduces to the interests of Christianity, and the welfare of society: impartially considered (1794), elicited the response Methodism vindicated from the charge of ignorance and enthusiasm, a reply to a sermon preached by S. Clapham, published at Margate in 1795.
The work drew particularly critical notice as an amateur compendium which, among other mistakes, stated that no case could be brought for verbal slander against a woman.
His only son, James Murray Clapham, had died on HMS Pandora on 28 April 1809, aged 18.