|Founded||February 10, 1808|
|Named for||the Delaware Indians|
|• Total||457 sq mi (1,180 km2)|
|• Land||443 sq mi (1,150 km2)|
|• Water||14 sq mi (40 km2) 3.1%%|
|• Density||470/sq mi (180/km2)|
|Time zone||UTC−5 (Eastern)|
|• Summer (DST)||UTC−4 (EDT)|
Delaware County is a county located in the central portion of the U.S. state of Ohio. It is a frequent placeholder on the List of highest-income counties in the United States. As of the 2020 census, the population was 214,124. Its county seat is Delaware. The county was formed in 1808 from Franklin County, Ohio. Both the county and its seat are named after the Delaware Indian tribe. Delaware County was listed as the 35th wealthiest county in the United States in 2020. Delaware County is included in the Columbus, Ohio Metropolitan Area. U.S. President Rutherford B. Hayes was born and raised in Delaware County. It is also home to the Columbus Zoo and Aquarium.
The area including Delaware County was once home to numerous Native American tribes. In 1804, Colonel Moses Byxbe and Henry Baldwin, among others, migrated to central Ohio from Berkshire County, Massachusetts, and built a town on the west bank of the Olentangy River. On February 10, 1808, the Ohio government authorized the creation of Delaware County. Following the War of 1812, settlers began to arrive in the county and settled down in Delaware. The town was incorporated in 1816, being the first incorporated town in the county. Powell, originally named Middlebury, was founded in 1801, but was not incorporated until 1947. Sunbury was founded in 1816. Ohio Wesleyan University, a liberal arts college, was founded by Methodists in 1842.
Delaware County had Northern sympathies during the Civil War, and abolitionists brought the Underground Railroad through the area. A local road, Africa Road, derives its name from the era. Camp Delaware was one of the few Civil War camps that deployed African American soldiers. The Civil War played an important part in Delaware County's growth, bringing railroad business and technology. By 1900, Delaware had its first electric streetway, and an electric interurban railroad connecting Marion and Columbus ran through the county. The Little Brown Jug race was founded in 1946, and is one of the races in the Triple Crown of Harness Racing for Pacers.
In 2008, Forbes magazine ranked Delaware County as the fifth best place in the United States to raise a family and the second best in Ohio, behind Geauga County. in 2020 Delaware was rated the best county to live in Ohio and 24th in the United States by Niche, 17th healthiest county by US News, and 24th best counties to live in by 247WallSt.
According to the U.S. Census Bureau, the county has a total area of 457 square miles (1,180 km2), of which 443 square miles (1,150 km2) is land and 14 square miles (36 km2) (3.1%) is water. The county has an even terrain and a fertile soil.
The major rivers of the county are the Scioto River, Olentangy River, Alum Creek, and the Big Walnut Creek. These waterways run from north to south across the county. The Alum Creek Lake and the Delaware Lake are reservoirs created on Alum Creek and the Olentangy River, respectively.
|U.S. Decennial Census|
1990-2000 2020 
As of the census of 2000, there were 109,989 people, 39,674 households, and 30,668 families living in the county. The population density is 249 people per square mile (96/km2). There were 42,374 housing units at an average density of 96 per square mile (37/km2). The racial makeup of the county was 94.25% White, 2.52% Black or African American, 0.14% Native American, 1.54% Asian, 0.03% Pacific Islander, 0.38% from other races, and 1.14% from two or more races. Hispanic or Latino of any race were 1.01% of the population. 26.8% were of German, 11.7% Irish, 11.3% English, 10.7% American and 6.9% Italian ancestry according to 2000 census.
There were 39,674 households, out of which 40.10% had children under the age of 18 living with them, 67.70% were married couples living together, 6.70% had a female householder with no husband present, and 22.70% were non-families. 18.10% of all households were made up of individuals, and 5.30% had someone living alone who was 65 years of age or older. The average household size was 2.70 and the average family size was 3.09.
In the county, the population was spread out, with 28.20% under the age of 18, 7.60% from 18 to 24, 32.60% from 25 to 44, 23.30% from 45 to 64, and 8.20% who were 65 years of age or older. The median age was 35 years. For every 100 females there were 98.00 males. For every 100 females age 18 and over, there were 94.90 males.
The median income for a household in the county was $67,258, and the median income for a family was $76,453. Males had a median income of $51,428 versus $33,041 for females. The per capita income for the county was $31,600. About 2.90% of families and 3.80% of the population were below the poverty line, including 4.40% of those under the age of 18 and 4.80% of those 65 and older.
By 2007, the median income for a household and for a family had risen to $80,526 and $94,099 respectively.
According to the United States Census Bureau, Delaware County is the 21st fastest growing county in the United States.
As of the 2010 United States Census, there were 174,214 people, 62,760 households, and 47,977 families living in the county. The population density was 393.2 inhabitants per square mile (151.8/km2). There were 66,378 housing units at an average density of 149.8 per square mile (57.8/km2). The racial makeup of the county was 89.7% white, 4.3% Asian, 3.4% black or African American, 0.1% American Indian, 0.6% from other races, and 1.8% from two or more races. Those of Hispanic or Latino origin made up 2.1% of the population. In terms of ancestry, 34.2% were German, 16.3% were Irish, 14.0% were English, 8.1% were Italian, and 5.7% were American.
Of the 62,760 households, 41.9% had children under the age of 18 living with them, 65.8% were married couples living together, 7.3% had a female householder with no husband present, 23.6% were non-families, and 19.0% of all households were made up of individuals. The average household size was 2.74 and the average family size was 3.16. The median age was 37.4 years.
The median income for a household in the county was $87,908 and the median income for a family was $101,698. Males had a median income of $70,949 versus $48,913 for females. The per capita income for the county was $40,682. About 3.4% of families and 4.6% of the population were below the poverty line, including 4.8% of those under age 18 and 5.4% of those age 65 or over.
Delaware County is considered a Republican stronghold, and has been so for most of the party's history. The only Democratic president candidate to win the county from 1856 to the present day was Woodrow Wilson in his 1912 & 1916 electoral victories. However, in 2020 Joe Biden came within single digits of flipping the county, the closest result since Lyndon Johnson’s landslide victory in 1964.
The following school districts are located in Delaware County.
The Ohio Wesleyan University, located in Delaware, Ohio, is one of the top liberal arts colleges in the United States and one of the Five Colleges of Ohio.
The area is served by the Delaware Municipal Airport, which serves the rapidly developing southern Delaware County area and the north portion of the Franklin County and Columbus areas. The airport contains a 5,000 foot runway, flight terminal, lounges, and weather briefing areas. It is home to approximately 80 aircraft and an estimated 40,000 operations take place per year. Several smaller airports are located in the county.
The Delaware Gazette, a morning daily founded in 1885, is the dominant local newspaper in Delaware County, while the Sunbury News, a weekly community newspaper, serves eastern Delaware County and residents of the Big Walnut Local School District. Both publications are owned by Brown Publishing Company.
Additional local print publications include ThisWeek Delaware News, which covers the city of Delaware and the villages of Galena and Sunbury; and ThisWeek Olentangy Valley News, which covers Powell and the Olentangy Local School District. Both weekly papers are among 21 published by ThisWeek Community News, headquartered in southern Delaware County. ThisWeek is owned by GateHouse Media, which also owns the Columbus Dispatch. The Village of Shawnee Hills in southwestern Delaware County is served by a monthly newspaper - The Village Gazette. The Village Gazette is independent.
Other local publications include the Transcript, the student paper at Ohio Wesleyan University.
Delaware, Ohio is famous for The Little Brown Jug, an internationally famous harness race which is part of the Triple Crown of harness racing.
The Methodist Theological School in Ohio is the Methodist graduate school seminary located between Delaware and Columbus, Ohio. It is often referred to as METHESCO.
Additional notable places include:
Notable people who have lived in or been associated with the county include: