Billy James Clark (January 4, 1778 in Northampton, Hampshire County, Massachusetts – September 20, 1866) was an American physician and politician from New York.
Later he removed to Moreau, New York, and practiced medicine there.
He was a member of the New York State Assembly (Saratoga Co.) in 1820.
In 1833, he removed to Glens Falls, and opened a drugstore there with Bethuel Peck.
He was a presidential elector in 1848, voting for Zachary Taylor and Millard Fillmore.