Reynolds was born in Lancaster, Pennsylvania and joined the Navy in 1831. His first assignment was to the USS Boxer, where he toured Africa, Brazil, and the Malay archipelago. In 1837, he was promoted to Passed Midshipman and then to Lieutenant in 1841. From 1838 to 1842, he served with the U.S. Exploring Expedition, and was among the first to sight the Antarctic mainland. In 1842, he was assigned to the USS Cumberland.
In 1862, he was promoted to Commander and given his first ship, the USS Vermont, a receiving ship at Port Royal, South Carolina. (When that ship was replaced by the USS New Hampshire, he was transferred to command it.) He was subsequently given command of the depot there.
In 1865, he was promoted to Captain and given command of the USS Lackawanna after the American Civil War, assigned to the Pacific. In 1867, he was the officer to formally claim the Midway Atoll for the United States, after its discovery by a sealing ship in 1859. In 1870, he was made a Commodore and was made the Chief of the Bureau of Equipment. In 1873, he was promoted to Rear Admiral and given command of the Asiatic Squadron from his flagship, the USS Tennessee. In 1877, due to failing health, he retired from active service.
- Rear-Admiral Reynolds. New York Times. New York, N.Y.: November 6, 1879. pg. 4, 1 pgs
- William Reynolds; Nathaniel Philbrick (2004). The Private Journal of William Reynolds : United States Exploring Expedition, 1838-1842. Penguin Classics. ISBN 9780143039051. http://books.google.com/books?id=4fUTBBP6xRwC.
- William Reynolds (US Navy officer) at Find a Grave Retrieved on 2009-05-06
fr:William Reynolds (explorateur)