William Webster Fisher, M.D, (1798 or 1799 – 4 October 1874), was Downing Professor of Medicine at Cambridge University.
He studied in the first instance at the University of Montpellier, where he befriended Auguste Comte and took the degree of M.D.
Elected to the Downing Professorship of Medicine in 1841, Fisher resigned his fellowship in 1844.
In addition to fulfilling the duties of his professorship, Fisher had a large practice as a physician at Cambridge.
Although for some time he had given up medical practice, he regularly delivered courses of lectures until 1868, after which they were read by a deputy, P. W. Latham, M.D., late fellow of Downing.