Mill Street business in downtown Orono. Orono (/ˈɒrənoʊ/) is a town in Penobscot County, Maine, United States. Located on the Penobscot and Still Water Rivers, it was first settled by Europeans in 1774 and named in honor of Chief Joseph Orono, a sachem of the Penobscot nation. It is home to the University of Maine. The town's population was 10,362 at the 2010 census.