Marlin—officially the Town of Krupp—is a town in Grant County, Washington, United States. The population was 49 at the 2020 census, the lowest of any incorporated municipality in Washington. Although legally incorporated as Krupp, the town is more commonly known as Marlin, which is the name of its post office. Elections are held there under the name of Marlin, Washington, and they are the same locale.
First settled in 1871 by Henry Marlin, the townsite was originally a cattle ranch that was later surrounded by wheat farms. The Great Northern Railway was built through the area in 1892 and placed a station, which was named Krupp—allegedly for a local German family. Its plat was filed in 1902 by George Urquhart, a Scottish immigrant who bought land rights and cattle from Marlin. The area was then settled by families who emigrated from Iowa and incorporated as the town of Krupp on January 7, 1911, despite not meeting the population threshold of 3