Dennis is a census-designated place and unincorporated community located at the intersection of Mississippi Highway 25 and Mississippi Highway 4 in Tishomingo County, Mississippi, United States. Dennis is approximately 6 miles (9.7 km) south of Tishomingo and 3 miles (4.8 km) north of Belmont. Although an unincorporated community, Dennis had a post office. Although it was shutdown some years ago. It was first named as a CDP in the 2020 Census which listed a population of 172.