Walter Gwynn (February 22, 1802 – February 6, 1882) was a civil engineer and soldier who became a Confederate general in the American Civil War.
Gwynn was born in Jefferson County, Virginia (now West Virginia), the son of Humphrey Gwynn, a descendent of Colonel Hugo Gwynn, who settled in Virginia before 1640. He graduated from the United States Military Academy at West Point, New York, in the Class of 1822 and was a commissioned a brevet second lieutenant in the 2nd U.S. Artillery, later transferring to the 4th U.S. Artillery. In 1827, while still an artillery lieutenant, he helped survey the route for the Baltimore and Ohio Railroad. He resigned his commission in February 1832. In 1833, he worked as an engineer in the building of the Portsmouth and Roanoke Railroad. He was Superintendent and Chief Engineer of the Wilmington and Raleigh Railroad in North Carolina from 1836 to 1840. In 1846, he became president of the James River and Kanawha Canal Company, which was funded by the Virginia Board of Public Works. By the late 1850s, Gwynn had established an international reputation as a railroad engineer and as a founder of the southeastern railroad network. A colleague said that Gwynn. "made for himself a reputation among his fellow engineers that will last for all time." In 1857, he retired from railroad work and moved to South Carolina.
At the start of the Civil War, Gwynn was a major in the engineers of the South Carolina Militia. At the request of the governor, he had accepted the commission and was charged with constructing batteries at various strategic points in Charleston Harbor, facing Fort Sumter. On April 10, 1861, he accepted a commission as major general of the Virginia Militia and was directed by Virginia governor John Letcher to assume command of the defenses around Norfolk and Portsmouth until mid-May. He also served as a brigadier general in the Virginia Provisional Army and then brigadier general in the North Carolina Militia, commanding the Northern Coast Defenses of North Carolina. All of these general-officer assignments were in the spring and summer of 1861. By August he joined the Confederate States Army as a major of engineers and was promoted to colonel on October 9, 1862.
Gwynn oversaw construction of defensive fortification at Sewell's Point, which was across the mouth of Hampton Roads from Fort Monroe at Old Point Comfort. In 1861, he participated in the Battle of Big Bethel during the Blockade of the Chesapeake Bay. In 1863, he resigned his commission and was named comptroller of the State of Florida.
After the war, Gwynn returned to civil engineering in North Carolina.
He died in Baltimore, Maryland, and is buried in Hollywood Cemetery, Richmond,