Isaac Alfred Fisher (12 April 1851 – 19 June 1944) was an umpire in one Test match in Australia in 1884. Fisher was born in Adelaide, South Australia, the youngest son of Thomas Fisher. Before taking up umpiring he played for Hindmarsh (later renamed West Torrens), his fellow players including Affie Jarvis and Frank King. Fisher continued to umpire first-class matches occasionally in the 1880s and 1890s – all but three in Adelaide – including Sheffield Shield matches in 1894/95, 1895/96 and 1896/97.