Northeast Ohio is a geographic and cultural region that comprises the northeastern counties of the U.S. state of Ohio. Definitions of the region consist of 16 to 23 counties between the southern shore of Lake Erie and the foothills of the Appalachian Mountains, home to over 4.5 million people. It is anchored by the metropolitan area of Cleveland, the most populous city in the region with over 372,000 residents in 2020. Other metropolitan centers include Akron, Canton, Mansfield, Sandusky, and Youngstown. Northeast Ohio includes most of the area known historically as the Connecticut Western Reserve.

Different sources define the region as having various boundaries. In its most expansive usage, it contains six metropolitan statistical areas: Cleveland–Elyria, Akron, Canton–Massillon, Youngstown–Warren, Mansfield, and Weirton–Steubenville along with eight micropolitan statistical areas. There are 23 counties in the region, with over 4.5 million residents and a labor force of almost 2.2 million. The GDP (nominal) of Northeast Ohio is over $195 billion, which makes it comparable to that of New Zealand or the Republic of Ireland.

Most of Northeast Ohio is part of the Cleveland–Akron–Canton Combined Statistical Area, which ranked as the 17th-largest Combined Statistical Area (CSA) in the United States as of the 2020 Census with a population of 3,769,834. It includes the six counties that make up Greater Cleveland (Cuyahoga, Lake, Geauga, Lorain, Medina, and Ashtabula), the Akron metropolitan area (Portage and Summit counties), the Canton–Massillon metropolitan area (Stark and Carroll counties), and the Sandusky metropolitan areas, in addition to the Norwalk, New Philadelphia–Dover, Wooster, Fremont, and Coshocton micropolitan areas.

The Cleveland–Akron–Canton media market covers much of this area, including all of Northeast Ohio except for the Youngstown/Warren region. It is the 19th largest in the United States as of 2023, according to Nielsen Media Research. Northeast Ohio and the Cleveland CSA are also part of the larger Great Lakes Megalopolis.

Northeast Ohio is home to a number of higher education institutions, including:

Northeast Ohio is home to a number of professional sports teams, including three from the major North American sports leagues. The Cleveland Guardians of Major League Baseball play at Progressive Field, Cleveland Browns of the National Football League (NFL) are based at Huntington Bank Field, and the Cleveland Cavaliers of the National Basketball Association (NBA) play at Rocket Arena. Rocket Arena is also home to one additional professional franchise, the Cleveland Monsters of the American Hockey League. The Monsters are the top minor league affiliate of the Columbus Blue Jackets of the National Hockey League (NHL).

There are a number of other professional sports teams in the region that play in various minor leagues. The Guardians have two minor league affiliates in the area: the AA Akron RubberDucks of the Eastern League who play at 7 17 Credit Union Park in Akron, and the High-A Lake County Captains of the Midwest League who play at Classic Park in Eastlake. The Mahoning Valley Scrappers, who play at Eastwood Field in Niles are members of the MLB Draft League since 2021. Additionally, there is an independent baseball team, the Lake Erie Crushers of the Frontier League, who play at Sprenger Stadium in Avon. The region also boasts of a lower league professional soccer team in Cleveland SC that plays at Don Shula Stadium. The Youngstown Phantoms are a junior ice hockey team in the United States Hockey League that has home games at Covelli Centre.

Motorsports venues in the region include Mid-Ohio Sports Car Course in Lexington and Summit Motorsports Park in Norwalk, a major NHRA venue.