USS YP-422 was a United States Navy yard patrol (YP) boat that served the United States Navy in World War II from 1942 to 1943. Built in 1941 as the fishing trawler Mist, she was acquired by the US Navy in June 1942 and was converted for naval use by George Lawley & Son of Neponset, Massachusetts. She was commissioned on 28 July 1942 and was put into service to patrol the waters around the Boston Navy Yard. The vessel was lightly armed with a 3-inch gun and two .30 caliber machine guns.