Isaac Fisher (1851 – 13 March 1932) was an English first-class cricketer and, more notably, a cricket umpire.
Born in Derby, Derbyshire, Fisher began his cricketing career as a player for Derbyshire County Cricket Club. He played first-class cricket for Derbyshire from 1871 until 1887, appearing in 111 matches. Primarily a right-handed batsman, he scored 2,878 runs at an average of 14.75, including one century. He also contributed as a right-arm medium-fast bowler, taking 79 wickets at an average of 25.13.
After retiring as a player, Fisher transitioned to umpiring, where he gained significant recognition. He stood in a total of 13 Test matches between 1899 and 1912, all of which were played in England. His inaugural Test match as an umpire was the first Test of the 1899 Ashes series between England and Australia at Trent Bridge, Nottingham, from 1-3 June 1899. His final Test appointment was the fifth Test of the 1912 Triangular Tournament, contested by England and Australia at The Oval, London, from 19-22 August 1912.
Fisher was a well-respected figure in English cricket during his active years as an umpire, overseeing many significant matches during a period of transition and professionalization in the sport. He passed away in Derby at the age of 80.