Charles John Morris Gwinn (also spelled Gwin;[1] October 21, 1822 – February 11, 1894) was an American lawyer and politician who served as attorney general of Maryland from 1875 to 1883.

He took office in January 1852 and served one four-year term, declining to seek reelection in 1855 and being replaced by Milton Whitney Sr. After serving as state's attorney, he returned to law, where he was lead counsel for the Baltimore and Ohio Railroad and counsel for several other people and companies.

He had three younger sisters, all of whom died unmarried and childless: Elizabeth M., Sarah M., and Emily Ann.

His political career began as a member of the Maryland House of Delegates from Baltimore in 1849,[2] serving alongside Sidnor S. Donaldson, Oliver F. Hack, John Marshall, and Charles S.

He was elected as the first state's attorney of Baltimore in 1851,[nb 1] defeating Whig candidate S. Teackle Wallis and taking office on January 5, 1852.

He became the lead counsel alongside Latrobe for the Baltimore and Ohio Railroad and a counsel for several people, including Arunah Shepherdson Abell and Johns Hopkins, and companies, including C&P Telephone; Robert Garrett & Sons, a bank; and the Western Union Telephone Company.

They had one child, Mary "Mamie" Mackall Gwinn, in 1861; she married Alfred Hodder in 1904 and died childless in 1940.