Northwest Ohio, or Northwestern Ohio, consists of multiple counties in the northwestern corner of the US state of Ohio. This area borders Lake Erie, Southeast Michigan, and northeastern Indiana. Some areas are also considered the Black Swamp area. The Toledo metropolitan area is part of the region.
Northwest Ohio's population in 2000 was 1,639,144 and is declining, specifically in the northern regions (counties shaded in the darker blue and Allen County). However, southern areas, such as Marion and Morrow Counties, and the City of Findlay are growing.