Isaac S. Mackie (23 September 1880 – 22 June 1963) was a Scottish-American professional golfer who played in the late 19th and early 20th century. He apprenticed as a club maker under George Forrester. Following his brother Jack—who had emigrated to the United States in 1899—Mackie also made the trans-Atlantic journey in 1901. He took a job as professional at Fox Hills Golf Club on Staten Island soon after his arrival and remained in that post until 1914. In 1916, he was appointed the head professional at Canoe Brook Country Club, replacing Louis Tellier. In 1953 he was the head professional at Netherwood Golf Club in North Plainfield, New Jersey.