James Mackin (December 25, 1822 in Newburgh, Orange County, New York – March 1887) was an American merchant, banker and politician.
He lived at Fishkill Landing where he was a merchant and real estate agent.
He was appointed Postmaster of Fishkill during the presidency of Zachary Taylor and kept the post for about four years.
On October 10, 1878, bank-robbers attempted to rob the First National Bank of Fishkill Landing of which Mackin was President.
He was buried in the churchyard of the Reformed Dutch Church at Fishkill Landing (now Beacon, New York) in the same vault with his first wife.