William Burnside (2 July 1852 – 21 August 1927) was an English mathematician. He is known mostly as an early researcher in the theory of finite groups.Burnside was born in London, and attended St. John's and Pembroke Colleges at the University of Cambridge, where he was the Second Wrangler in 1875. He lectured at Cambridge for the following ten years, before being appointed professor of mathematics at the Royal Naval College in Greenwich.