Commander William Lewis Herndon (25 October 1813 – 12 September 1857) was one of the United States Navy's outstanding explorers and seamen.

He was noted especially for ensuring the rescue of 152 women and children when commanding the commercial mail steamer Central America in September 1857.

[2] He married Frances Elizabeth Hansborough and they had a daughter, Ellen Lewis Herndon (future wife of Chester A. Arthur), born in Culpeper Court House, Virginia.

From 1842 to 1846, Herndon served in the Depot of Charts and Instruments of the US Naval Observatory with his first cousin and brother-in-law, Matthew Fontaine Maury.

In 1851, Herndon headed an expedition exploring the Valley of the Amazon, a vast area uncharted by Europeans, although inhabited for thousands of years by numerous tribes of indigenous peoples.

[3] After a journey of 4,366 miles (7,026 km), which took him through the wilderness from sea level to heights of 16,199 feet (4,937 m), Herndon reached the city of Pará, Brazil on 11 April 1852.

[3] After two years of active service on Potomac and San Jacinto, Herndon was assigned in 1855 as commander of the Atlantic Mail Steamship Company steamer SS Central America, on the New York to Aspinwall, Panama, run.

Navy captains were assigned to command the mail steamers on the Atlantic and Pacific runs; the ships were operated and maintained by companies under contract to the federal government.

Herndon was carrying perhaps 15 tons of gold (then worth $2,000,000) and 474 passengers, many of whom were from California and were returning to the East Coast, as well as 101 crew members.

Some were rescued later by passing vessels, but most of the 423 persons on board died in what was the largest loss of life for a commercial ship in United States history.