John Sidney Smith was an American politician and a member of the Democratic Party. He served as a U.S. Representative from Virginia during the early 19th century. Smith was known for his involvement in local and national politics, contributing to various legislative efforts during his time in office. In addition to his political career, Smith was also engaged in law and served in several local government positions. His work helped shape the political landscape of Virginia during a period of significant change in the United States, particularly as the nation expanded westward.