James McHenry (December 20, 1785 – July 21, 1845) was an American writer, physician, and diplomat.
He was born at Larne, Ireland and was educated in Dublin and Glasgow, In 1817 he emigrated to the United States and took up residence in Philadelphia, where he practised medicine. He was appointed in 1842 as United States counsel at Derry.
He died at Larne, on 21 July 1845. 
His son James, who died in 1891 at Kensington, was a well-known financier. His daughter Mary married Mr. J. Bellargee Cox of Philadelphia.