Charles Thomas Hudson (11 March 1828 – 23 October 1903) was an English naturalist, particularly interested in microscopical research, and in the microscopic animal rotifer.
He was born in 1828 in Brompton, London, third of five sons of John Corrie Hudson, chief clerk of the Legacy Duty Office, and wife Emily. His father in youth was an advanced radical and friend of William Godwin, of the Shelleys, Charles Lamb and William Hazlitt.
He was educated at Kensington Grammar School and The Grange, Sunderland. He was musical, and as a young man wrote and composed songs. Family circumstances compelled him to earn his living by teaching at an early age, in Glasgow and later at the Liverpool Royal Institution. In 1848 he went to St John's College, Cambridge, where he graduated in 1852, proceeding M.A. in 1855 and LL.D. in 1866. After leaving Cambridge he became on 25 July 1852 second master of Bristol Grammar School, and on 30 March 1855 he was appointed headmaster.
He resigned this post at midsummer 1860, and in 1861 opened a private school at Manilla Hall, Clifton, Bristol, formerly the residence of Sir William Draper, which he conducted until 1881. His varied interests and sympathies made the school successful. Afterwards he lived at 6 Royal York Crescent, Clifton; in 1891 he moved to Dawlish, Devon, and in 1899 to Shanklin, Isle of Wight. During his later years he often gave lectures, chiefly at public schools, on natural history, which he illustrated with coloured transparencies of his own construction.
Hudson devoted his leisure to microscopical research, and in particular to the study of the Rotifera. His first printed paper was on Rhinops Vitrea in the Annals and Magazine of Natural History for 1869. Afterwards he published numerous papers in the Microscopical Journal and the Quarterly Journal of Microscopical Science, describing new genera and species of Rotifera, of which Pedahon mirum was a notable discovery. A list of these papers is given in the Journal of the Royal Microscopical Society for 1904, page 49.