Cleveland is a city in the state of Ohio and the county seat of Cuyahoga County, the most populous county in the state. The municipality is located in northeastern Ohio on the southern shore of Lake Erie, approximately 60 miles west of the Pennsylvania border. It was founded in 1796 near the mouth of the Cuyahoga River, and became a manufacturing center owing to its location at the head of numerous canals and railroad lines. With the decline of heavy manufacturing, Cleveland's businesses have diversified into the service economy, including the financial services, insurance, legal, and healthcare sectors, though the city's population has continued to decline. Cleveland is also noted for its association with rock music; the city is home to the Rock and Roll Hall of Fame.

As of the 2000 Census, the city proper had a total population of 478,403, and was then the 33rd largest city in the United States, and the second largest city in Ohio. It is the center of Greater Cleveland, the largest metropolitan area in Ohio, which spans several counties and is defined in several different ways by the Census Bureau. The Cleveland-Elyria-Mentor Metropolitan Statistical Area which in 2000 ranked as the 23rd largest in the United States with 2,250,871 people. Cleveland is also part of the larger Cleveland-Akron-Elyria Combined Statistical Area, which in 2000 had a population of 2,945,831, and ranked as the country's 14th largest.

In studies conducted by The Economist in 2005, Cleveland and Pittsburgh were ranked as the most livable cities in the United States, and the city was ranked as the best city for business meetings in the continental U.S. The city faces continuing challenges, in particular from concentrated poverty in some neighborhoods and difficulties in the funding and delivery of high-quality public education.

Residents of Cleveland are usually referred to as "Clevelanders." Nicknames used for the city include "The Forest City," "The Cleve," "The Land," "Metropolis of the Western Reserve," "The New American City," "America's North Coast," "Sixth City," "Rock 'n' Roll Capital of the World" (because of the Rock and Roll Hall of Fame), and "C-Town."

Cleveland obtained its name on July 22, 1796 when surveyors of the Connecticut Land Company laid out Connecticut's Western Reserve into townships and a capital city they named "Cleaveland" after their leader, General Moses Cleaveland. Cleaveland oversaw the plan for the modern downtown area, centered on the Public Square, before returning home, never again to visit Ohio. The first settler in Cleaveland was Lorenzo Carter, who built a cabin on the banks of the Cuyahoga River. The Village of Cleaveland was incorporated on December 23, 1814. The spelling of the city's name was later changed to "Cleveland" when, in 1831, an "a" was dropped so the name could fit a newspaper's masthead.

In spite of the nearby swampy lowlands and harsh winters, its waterfront location proved to be an advantage. The area began rapid growth after the 1832 completion of the Ohio and Erie Canal. This key link between the Ohio River and the Great Lakes connected the city to the Atlantic Ocean via the Erie Canal and later via the St. Lawrence Seaway; and the Gulf of Mexico via the Mississippi River. Growth continued with added railroad links. Cleveland incorporated as a city in 1836.

In 1836, the city, then located only on the eastern banks of the Cuyahoga River, nearly erupted into open warfare with neighboring Ohio City over a bridge connecting the two. Ohio City remained an independent municipality until it was annexed by Cleveland in 1854. The site flourished as a halfway point for iron ore from Minnesota shipped across the Great Lakes and other raw materials (coal) carried by rail from the south. Cleveland emerged as a major American manufacturing center, home to numerous major steel producers, as well as a number of carmakers, including gasoline cars Peerless, People's, Jordan, Winton (first car driven across the U.S.), steam car builders White and Gaeth, and electric car company Baker. By 1920, Standard Oil founder John D. Rockefeller had made his fortune and Cleveland had become the fifth largest city in the country. The city was a center for the national progressive movement, headed locally by Mayor Tom L. Johnson. Many Clevelanders of this era are buried in the historic Lake View Cemetery, along with James A. Garfield, the twentieth U.S. President.

In commemoration of the centennial of Cleveland's incorporation as a city, the Great Lakes Exposition debuted in June 1936 along the Lake Erie shore north of downtown. Conceived as a way to energize a city hit hard by the Great Depression, it drew 4 million visitors in its first season, and 7 million by the end of its second and final season in September 1937. The exposition was housed on grounds that are now used by the Great Lakes Science Center, the Rock and Roll Hall of Fame and Burke Lakefront Airport, among others.

Immediately after World War II, the city experienced a brief boom. In sports, the Indians won the 1948 World Series and the Browns dominated professional football in the 1950s. Businesses proclaimed that Cleveland was the "best location in the nation." The city's population reached its peak of 914,808, and in 1949 Cleveland was named an All-America City for the first time. By the 1960s, however, heavy industries began to slump, and residents sought new housing in the suburbs, reflecting the national trends of white flight and urban sprawl. Like other major American cities, Cleveland also began witnessing racial unrest, culminating in the Hough Riots from July 18, 1966 – July 23, 1966 and the Glenville Shootout on July 23, 1968 – July 25, 1968. The city's nadir is often considered to be its default on its loans on December 15, 1978, when under Mayor Dennis Kucinich it became the first major American city to enter default since the Great Depression. National media began referring to Cleveland as "the mistake on the lake" around this time, in reference to the city's financial difficulties, a notorious 1969 fire on the Cuyahoga River (where industrial waste on the river's surface caught on fire), and its struggling professional sports teams. The city has worked to shed this nickname ever since, though in recent times the national media have been much kinder to the city, using it as an exemplar for public-private partnerships, downtown revitalization, and urban renaissance.

The metropolitan area began recovery thereafter under Mayors George Voinovich and Michael R. White. Redevelopment within the city limits has been strongest in the downtown area near the Gateway complex—consisting of Progressive Field and Quicken Loans Arena, and near North Coast Harbor—including the Rock and Roll Hall of Fame, Cleveland Browns Stadium, and the Great Lakes Science Center. Although Cleveland was hailed by the media as the "Comeback City," many of the inner-city residential neighborhoods remain troubled, and the public school system continues to experience serious problems. Economic development, retention of young professionals, and capitalizing upon its waterfront are current municipal priorities. In 1999, Cleveland was identified as an emerging global city.