John Blissard (23 May 1803 – 10 December 1875) was a Church of England vicar, educator, and mathematician who invented what came to be known as the umbral calculus. Although he never held a university post, Blissard was an active mathematician, especially during the 1860s when he was in his late fifties and early sixties. He published mostly in the Cambridge-based Quarterly Journal of Pure and Applied Mathematics.