James J. Mutrie (June 13, 1851 - January 24, 1938) was an American baseball pioneer who was the co-founder and first manager of both the original New York Metropolitans and the New York Giants. His career winning percentage of .611 was a 19th-century record, and remains the second highest by any major league manager with at least 500 wins, trailing only Joe McCarthy's mark of .615.
Mutrie, nicknamed "Smilin' Jeems" and "Truthful Jim", was born in Chelsea, Massachusetts and grew up playing cricket, first playing baseball at age 16. In 1880 he moved from New England to New York, where he obtained financial backing from August Belmont and John B. Day to start the independent New York Metropolitans. At the end of the 1882 season, Day and Mutrie accepted offers from both the American Association and the National League to enter a New York team; they met their double commitment by entering the Mets in the American Association, and acquiring most of the players from the Troy Trojans to form the New York Gothams for the National League.
Mutrie managed the Metropolitans in 1883 and 1884, leading them to the 1884 World Series the latter year. In 1885, he switched to managing the Gothams, and is credited with giving them their nickname, the Giants. With star players such as Buck Ewing, Tim Keefe, and Roger Connor, the Giants won National League pennants and World Series titles under Mutrie in 1888 and 1889. Ewing, Keefe, and many other players defected to the Players League's New York Giants in 1890, and the National League Giants under Mutrie slumped to sixth and then third place. When the Giants were reorganized after the 1891 season under new ownership, Mutrie was not retained as manager.
After leaving baseball, Mutrie operated a hotel in Elmira, New York and a newsstand on Staten Island. He died of cancer on Roosevelt Island in New York City at age 86.