Walter Gwynn (1802-1882) was an American civil engineer and soldier. He graduated from the United States Military Academy at West Point, New York in the Class of 1822. In 1827, he helped survey the route for the Baltimore and Ohio Railroad. In 1833, he was involved and 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.

Walter Gwynn was a Brigadier General in the Confederate Army during the American Civil War. In 1861, he was directed by Virginia governor John Letcher to assume command of the defenses around Norfolk and Portsmouth. He 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 1862, he participated in the Battle of Big Bethel during the Peninsula Campaign. In 1863, he was named comptroller of the State of Florida.

After the war, he returned to civil engineering in North Carolina.

He died in 1882.