The population was 35,318 at the 2000 census. According to the US Census 2007 estimate, Marion has a population of 35,686, while Ohio's Columbus–Marion–Chillicothe Combined Statistical Area has 1,982,252 people. Marion is the county's largest city and the center of the Marion Micropolitan Statistical Area (as defined by the United States Census Bureau in 2003). It is nicknamed the World's Popcorn Capital. President Warren G. Harding was a native of Marion.
Best known as the hometown and burial location of President Warren G. Harding and First Lady Florence Harding, Marion was one of Ohio's major industrial centers until the 1970s. Products of the Marion Steam Shovel Company (later Marion Power Shovel) built the Panama Canal and in the 1960s, NASA contracted with Power Shovel to construct the crawler-transporters that moved the assembled Saturn V rockets, used by Project Apollo, to the launch pad. In 1911, 80% of the nation's steam shovel and heavy duty earth moving equipment was manufactured in Marion, Ohio.
The city is also a rail center for CSX, and Norfolk Southern, linking all four points on the compass. Marion is the nation's leader in corn and popcorn produced foods. Whirlpool Corporation of Benton Harbor, Michigan is the largest employer in the city operating the largest clothes dryer manufacturing facility in the world.
Marion is also the birthplace and childhood home of Norman Mattoon Thomas, four-time candidate for President of the United States under the Socialist Party of America ticket and co-founder of the American Civil Liberties Union (ACLU). Elsie Janis, the stage name for Elsie Beerbower, musical theatre star and "Sweethert of the American Expeditionary Forces" (AEF) during World War I was a native of Marion County. The Isaly family of Mansfield, Ohio - inventors of the Klondike bar - chose Marion as the second Isaly's Dairy facility.
In 1938, local tap dance instructor Marilyn Meseke, was crowned Miss America 1938 - the first year that talent was considered part of the annual competition. Meseke's trophy and pageant memorabilia is housed at the Marion County Historical Society.
Mary Ellen Withrow (nee Hinamon), Treasurer of the United States from 1994 until 2001 is a Marion County native. Withrow is the only person in the history of the United States to have held the governmental position of Treasurer on the Local (Marion County Ohio Treasurer), State (Treasurer of the State of Ohio) and Federal levels of Government.
Marion Cemetery also has the dubious honor of being home to the Merchant family grave marker, known in paranormal circles for its unintended movements. The marker consists of a large grey granite pedestal capped by a two-ton granite sphere four feet in diameter. The sphere moves on its base several inches every year, as measured by the distance traveled by the unpolished spot on what was originally where the sphere's bottom was mated to the pedestal. While the movement of the sphere is thought to be facilitated by freeze-thaw cycles, earth tremors, or trapped air or water under the base, there has been no conclusive explanation for patterns that the sphere seems to follow. The movements of the sphere have been documented by numerous news outlets and it has been featured in Ripley's Believe it or Not (September 29, 1927).
The city is located about 50 miles (80 km) north of Ohio's capital city, Columbus, due north along U.S. Highway 23. Marion occupies most of Marion Township, which is located just outside of the city limits.
According to the United States Census Bureau, the city has a total area of 11.4 square miles (29.5 km²), of which, 11.4 square miles (29.4 km²) of it is land and 0.04 square miles (0.1 km²) of it (0.35%) is water.
There were 13,551 households out of which 31.6% had children under the age of 18 living with them, 46.3% were married couples living together, 14.1% had a female householder with no husband present, and 34.9% were non-families. 29.3% of all households were made up of individuals and 12.0% had someone living alone who was 65 years of age or older. The average household size was 2.44 and the average family size was 3.00.
In the city the population was spread out with 25.2% under the age of 18, 9.3% from 18 to 24, 30.8% from 25 to 44, 21.5% from 45 to 64, and 13.2% who were 65 years of age or older. The median age was 35 years. For every 100 females there were 102.3 males. For every 100 females age 18 and over, there were 101.5 males.
The median income for a household in the city was $33,124, and the median income for a family was $40,000. Males had a median income of $31,126 versus $22,211 for females. The per capita income for the city was $16,247. About 10.9% of families and 13.8% of the population were below the poverty line, including 20.2% of those under age 18 and 6.9% of those age 65 or over.
Among Marion's notable radio stations are WMRN (94.3FM) country music station, WMRN (1490AM) news/talk (clear channel), WOSB (91.1FM) NPR News and classical music station, WYNT (95.9FM) adult contemporary station, and WDCM (97.5FM) community radio.
The local t.v. station is ch 39, which is mainly christian style programing.
Marion is home to two institutions of higher learning. The Ohio State University has a regional campus at Marion, and Marion Technical College, a community college that shares the Marion Campus with OSU.