James John Hart (November 27, 1875 – August 31, 1926) was a Major League Baseball first baseman.
Hart played for the Baltimore Orioles in 1901.
In 58 career games, he had 64 hits in 206 at-bats, with 23 RBIs.
He batted right and left-handed.
On August 5, 1901 Hart punched umpire John Haskell after being called out at third base.
American League president Ban Johnson suspended Hart as result of the incident:
"This is the first time a player in the American League has struck an umpire‚ and it is an offense that cannot be overlooked."