Rear Admiral William Mayhew Folger (19 May 1844 – 22 July 1928) was an officer in the United States Navy. He served in the American Civil War without seeing action. He filled a wide range of roles, including Chief of the Bureau of Ordnance, over the following 30 years. He fought in the Spanish–American War as captain of the protected cruiser USS New Orleans. Folger served as a lighthouse inspector before becoming commander of the Philippine Squadron during the Philippine–American War, and was briefly Commander-in-Chief of the United States Asiatic Fleet. He retired in 1905 as a rear admiral.