John Jackson McSwain (born May 1, 1875) was a Democratic member of the United States House of Representatives from South Carolina. Representing the state’s 4th Congressional District, he served eight terms in Congress. His tenure in the House began on April 11, 1921, and continued until January 3, 1937, marking a legislative career that spanned more than fifteen years.

During his time in office, McSwain served as a Representative for South Carolina in the U.S. Congress, participating in national lawmaking through the 1920s and into the mid-1930s. Identified in congressional records by the bioguide ID M000604, he was part of the Democratic Party’s delegation from the South at a time of significant political and economic change in the United States. McSwain left office as a former member of Congress after his service concluded in early 1937.