Adelphi is a village located in Ross County, in the state of Ohio (OH), United States. Nestled in the East North Central division of the Midwest region, it covers an area of 0.3 square miles (1.0 km²) and sits at an elevation of 838 ft. With a population of approximately 371 residents, Adelphi offers a peaceful, rural atmosphere.
The town's population is composed of about 50.4% males and 49.6% females, and it has a population density of 325.00 people per square mile (511.59/km²). Adelphi lies at a latitude of 39.47 and a longitude of -82.75, operating in the UTC-5.
Locals reflect a blend of American ancestry, with roots primarily in United States (20.2%), followed by English (5.9%), German (18.9%), and Scotch-Irish (0%) heritage. The town is identified by the ZIP code 43101.