Delphos is a city in Allen and Van Wert counties in the U.S. state of Ohio approximately 14 mi northwest of Lima and 13 mi east of Van Wert. The population was 7,117 at the 2020 census. The Allen County portion of Delphos is part of the Lima Metropolitan Statistical Area, while the Van Wert County portion is part of the Van Wert Micropolitan Statistical Area.