James Adger Smyth (June 8, 1837 – April 25, 1920) was Mayor of Charleston, South Carolina for two terms between 1896 and 1903.

He graduated from the College of Charleston in 1858 and began working at his uncles' wholesale hardware firm, J.E.

In 1862, he enlisted and fought with Company A of the 25th Regiment of the South Carolina Volunteers until the end of the Civil War in 1865.

In 1875, Smyth became an independent cotton broker, and along with his cousin, Andrew Moffett Adger, started the company Smyth and Adger, successfully brokering cotton from North Carolina, Georgia, and Alabama.

He was member of the State and County Democratic Executive Committees (1876), City Council (1885), and mayor for two four-year terms (1895 to 1903).