Jay James O'Brien (February 22, 1883 – April 5, 1940) was an American bobsledder who competed in the late 1920s and early 1930s. He won two medals at the Winter Olympics with a gold in the four-man event at Lake Placid, New York, in 1932 and a silver in the five-man event at St. Moritz in 1928. At 48 years old, he was the oldest Olympic champion.
O'Brien was also a jockey, and was head of the United States Olympic Bobsled Committee at the time of the 1932 Winter Olympics in Lake Placid. He died of a heart attack in 1940.
Bobsleigh five-man Olympic medalists for 1928 Archived 2017-01-06 at the Wayback Machine
Wallenchinsky, David. (1984). "Bobsled: Four-Man". In The Complete Book of the Olympics: 1896-1980. New York: Penguin Books. p. 560.