Barclay Coppock (January 4, 1839 – September 4, 1861) was a follower of John Brown and a Union Army soldier in the American Civil War. Along with his brother Edwin Coppock (June 30, 1835 – December 16, 1859), he participated in Brown's raid on Harpers Ferry. In historic documents their last name was variously spelled "Coppock", "Coppoc", or "Coppac". The Coppock brothers were raised in Springdale, Iowa, where they met Brown while he was raising support for his Kansas anti-slavery raids. Edwin was hanged in Charlestown, Virginia, while Barclay eventually escaped to Canada; his flight was aided by Iowa governor Samuel Kirkwood, who refused to extradite him when Barclay was discovered hiding in Iowa. Edwin Coppock is buried in Hope Cemetery in Salem, Ohio. Barclay later joined the Union Army