|Occupations||Mathematician Historian of mathematics Lawyer Stage magician Educator|
|A.K.A.||Walter William Rouse Ball, Walter Ball|
|Birth||August 14, 1850 (Hampstead, London Borough of Camden, Greater London, London)|
|Death||April 4, 1925 (Cambridge, Cambridge, Cambridgeshire (county council area), Cambridgeshire)|
|Education||University College London, Trinity College|
Walter William Rouse Ball, known as W. W. Rouse Ball (; 14 August 1850 – 4 April 1925), was a British mathematician, lawyer, and fellow at Trinity College, Cambridge from 1878 to 1905. He was also a keen amateur magician, and the founding president of the Cambridge Pentacle Club in 1919, one of the world's oldest magic societies.
Ball was the son and heir of Walter Frederick Ball, of 3, St John's Park Villas, South Hampstead, London. Educated at University College School, he entered Trinity College, Cambridge in 1870, became a scholar and first Smith's Prizeman, and gained his BA in 1874 as second Wrangler. He became a Fellow of Trinity in 1875, and remained one for the rest of his life.
He is buried at the Parish of the Ascension Burial Ground in Cambridge.
He is commemorated in the naming of the small pavilion, now used as changing rooms and toilets, on Jesus Green in Cambridge.
- A History of the Study of Mathematics at Cambridge; Cambridge University Press, 1889 (reissued by the publisher, 2009, ISBN 978-1-108-00207-3)
- A Short Account of the History of Mathematics at Project Gutenberg (1st ed. 1888 and later editions). Dover 1960 republication of fourth edition: .
- Mathematical Recreations and Essays at Project Gutenberg (1st ed. 1892; later editions with H.S.M. Coxeter)
- A History of the First Trinity Boat Club (1908)