Nāʻālehu is a community in Hawaiʻi County, Hawaii, United States. Nāʻālehu is Hawaiian for "the volcanic ashes". It is one of the southernmost communities with a post office in the 50 states of the United States. For statistical purposes, the United States Census Bureau has defined Naalehu as a census-designated place. The census definition of the area may not precisely correspond to local understanding of the area with the same name.