James B. McCoy (April 22, 1839 – 1911) was a member of the Wisconsin State Assembly.
During the American Civil War, McCoy served with the 25th Wisconsin Volunteer Infantry Regiment of the Union Army.
Originally an enlisted man, he achieved the rank of first lieutenant.
He died of an intestinal ailment in late July or early August 1911.
Previously, he had been elected Sheriff of Grant County, Wisconsin, in 1874.