John Joseph Flanagan (sometimes spelled Flannigan;[1][2] January 28, 1868 – June 3, 1938) was an Irish-American three-time Olympic gold medalist in the hammer throw, winning in 1900, 1904, and 1908.

[3] John Flanagan was born in the townland of Ballinvreena[4] and raised in Kilbreedy East, near Martinstown in County Limerick, Ireland.

John was the first son of Ellen Kinkead and Michael Flanagan (married Feb 1867), then a farm steward for the Gabbett's of Kilmallock.

Flanagan joined the New York City Police Department (NYPD) in 1903, and his first assignment was to the Bureau of Licenses, where he had a lot of time on his hands, which was mostly used to train at the Irish American Athletic Club in Queens.

In the 1904 Olympic Games, sporting the Winged Fist of the Irish American Athletic Club, Flanagan set a new world record of 168 feet, 1 inch.

Following his retirement, he coached a number of athletes, including Patrick O'Callaghan, who went on to win two Olympic gold medals in the hammer throw at the 1928 and 1932 games.