James Nathaniel Halpin (October 4, 1863 – January 4, 1893), a native of England, was a Major League Baseball shortstop/third baseman. He played for the Worcester Ruby Legs (1882), Washington Nationals (1884 Union Association), and Detroit Wolverines (1885). At just 18 years of age, he was the youngest player to appear in a National League game in 1882. In 63 total games he hit .165 (38-for-230) with 5 doubles and 27 runs scored. He was a slightly below-average fielder for his era, making 51 errors in 263 total chances (.806). Halpin died at the age of 29 in Boston, Massachusetts.