|This article does not cite any references or sources. (May 2009)|
Northwest or northwestern Ohio consists of multiple counties in the northwestern corner of the United States state of Ohio. This area borders Lake Erie, southern Michigan, and eastern Indiana. Some areas in northwestern Ohio are also considered the Black Swamp area. The Toledo metropolitan area is also part of the region. Just like any other region, there is no universally agreed-upon boundary for northwestern Ohio, as the entire area is defined differently by the opinions of multiple people.
The area's population in the year 2000 was 1,639,144. The area is declining in population, specifically in the northern regions (counties shaded in the darker blue and Allen County). Southern areas such as Marion and Morrow counties as well as the city of Findlay are growing.
 Places considered within northwest Ohio
These places are or may be classified as being in northwestern Ohio, depending on the definition being applied:
 Counties & county seats
 Other cities, villages, and townships
If a city is a county seat, it has been listed above according to the county in which it lies. Many of the cities, townships, and villages in northwest Ohio are clustered in the Toledo MSA. This list is incomplete.
 Toledo area townships
 Other places
 Extreme Northwest Ohio
Extreme Northwest Ohio, or Far N'western Ohio, is a portion of Northwest Ohio best known as the Great Black Swamp area due to its natural history. The counties of Defiance, Fulton, Henry, Paulding, Putnam, Van Wert, and Williams in the state of Ohio are usually classified as extreme northwest Ohio.
According to the 2000 Census, the population of this portion of NW Ohio is 234,660. When Allen and Hancock counties are included, the population is 414,428. Just like any other region, there is no universally agreed-upon line for northwestern Ohio, as the entire area is defined differently by the opinions of multiple people.
 Principal Cities
|City||Population (2000 Census)|
|Bryan (Williams County)||8,333|
|Defiance (Defiance County)||16,465|
|Findlay (Hancock County)||38,967|
|Lima (Allen County)||40,081|
Toledo Express Airport (TOL), in suburban Swanton, is the largest airport in northwest Ohio. Toledo Express is served by seven major passenger airlines, and has been named one of the five best small airports in the Midwest. Toledo Express is also a major air cargo center, serving as the international hub for BAX Global. Toledo Express has begun a $22 million renovation project; As of 2007, the airport has expanded and renovated the central gate area of its single terminal, and is seeking an airline to offer direct service to New York City.
Toledo Express also hosts the corporate flight departments of Owens-Illinois, Owens-Corning, Pilkington, and Dana Corporation. Grand Aire Express offers charter and air taxi services from its base at the airport. In education, the airport is a base of operations for FlightSafety International and Toledo Public Schools' aviation program, with flight instruction also offered by the airport's two fixed-base operators, who also provide fuel, repair, and storage for general aviation aircraft. Additionally, Toledo Express is a base for F-16 fighter jets of the Ohio Air National Guard, which has provided the airport additional funding for runway lengthening and safety enhancements.
Detroit Metropolitan Airport to the north, Port Columbus International Airport to the southeast, and Cleveland Hopkins International Airport to the east are the major or hub airports serving residents of northwest Ohio. Detroit Metro is a "fortress hub" for Delta Airlines and offers both domestic and international flights. Port Columbus is the national hub for Skybus Airlines and offers primarily domestic flights. Cleveland Hopkins is a hub for United Airlines and offers both domestic and international flights.
Charter and air taxi service is also available at several smaller airports, such as Toledo Metcalf Field, Findlay Airport, and Lima Allen County Airport. General aviation users can also land at any one of approximately 40 public-use airports (both publicly and privately owned) in northwest Ohio.
The Williams County Airport in Bryan has the second longest runway in Northwest Ohio (Next to Toledo), making it the only other airport able to land larger aircraft in the region.
 Notable people
- Neil Armstrong, the first person to walk on the moon, was born in Wapakoneta in Auglaize County. The Neil Armstrong Air and Space Museum is named to honor his achievements.
- Figure Skater Alissa Czisny is from Bowling Green in Wood County. She won a bronze medal at the 2007 United States Figure Skating Championships in Spokane.
- Actor Jamie Farr, best known as Corporal Maxwell Klinger from the TV series M*A*S*H, is from Toledo.
- Former president Gerald Ford's wife Betty Ford lived in Toledo for a short period of time in the 1940s with her ex-husband before marrying Gerald Ford.
- Stephen Hadley, National Security Advisor to President George W. Bush, was born in Toledo and lived in Ottawa Hills, Ohio, until his family moved to the Cleveland area.
- Olympic Figure Skater Scott Hamilton is from Bowling Green in Wood County. He won a gold medal at the 1984 Olympic Games in Sarajevo, Bosnia-Herzegovina.
- Rutherford B. Hayes, 19th president of the United States, lived in Fremont, Ohio.
- Actress Katie Holmes is from Sylvania Township in Lucas County.
- 2006 Indianapolis 500 winner, 3 time Indy Car champion, and current NASCAR driver Sam Hornish Jr. was born in Bryan, grew up in Defiance, and now lives in Napoleon.
- Children's television show host Frances Horwich, also known as "Miss Frances", was born in Ottawa, Putnam County.
- American Atheists founder Madalyn Murray O'Hair graduated from Rossford High School.
- Kenneth Richey, an 18-year death row inmate who was born in the Netherlands and convicted of murder in Putnam County.
- Pittsburgh Steelers' quarterback and Super Bowl champion Ben Roethlisberger is from Findlay in Hancock County.
- Teresa Brewer, a popular jazz and traditional pop music singer, was a native of Toledo.
- Guitarist Tom Scholz of the rock band Boston is from Ottawa Hills.
- Noted feminist Gloria Steinem is from Toledo. Her grandmother, Pauline Steinem, was the first woman (and thus, the first Jewish woman) elected to the Toledo Board of Education.