John Flanagan is a three-time Olympic champion in the hammer throw (1900, Paris; 1904, St Louis; 1908, London) and a 1981 Hall of Fame inductee.

Flanagan was born in County Limerick, Ireland, in 1873. After moving to the US in 1896, Flanagan competed for the Irish American Athletic Club and then for the NYAC. Flanagan was a member of the “Irish Whales”: a group of Irish American throwers that dominated the sport, which included fellow NYAC members Matt McGrath and Patrick McDonald. 

Despite having only emigrated from Ireland four years earlier, Flanagan competed for the United States in the 1900 Olympic Games in Paris. At those Games, Flanagan won his first of three gold medals in the hammer throw, with a throw of 51.01m (167’ 4 ½”). Flanagan did not relinquish the title of “Olympic Champion” until fellow NYAC member Matt McGrath won the gold medal at the 1912 Games in Stockholm.  
Flanagan dominated the hammer throw for the next two Olympic Games – excluding the 1906 Inter-Calated Games in Athens, at which the hammer throw was not held. Notably, his throws in the 1904 St Louis Games (51.23m / 168' 1") and the 1908 London Games (51.93m / 170' 4 ¼") were both Olympic records. In addition to his three consecutive Olympic championships in the hammer throw, Flanagan also won the silver medal in the weight throw in 1904.

After retiring from competition, Flanagan moved back to Ireland to coach the legendary thrower Pat O'Callaghan. Under Flanagan's tutelage, O'Callaghan won Olympic championships in 1928 and 1932. 

Flanagan died on June 3rd, 1938 at the age of 70.