Adjacent counties

• Marion County (northeast)
• Butler County (east)
• Sedgwick County (south)
• Reno County (west)
• McPherson County (northwest)

2000 census

As of the 2000 census,^[11] there were 32,869 people, 12,581 households, and 8,932 families residing in the county. The population density was 61 inhabitants per square mile (24/km²). There were 13,378 housing units at an average density of 25 per square mile (9.7/km²). The racial makeup of the county was 91.04% White, 1.59% Black or African American, 0.52% Native American, 0.52% Asian, 0.03% Pacific Islander, 4.17% from other races, and 2.14% from two or more races. Hispanic or Latino of any race were 7.97% of the population.

There were 12,581 households, out of which 32.80% had children under the age of 18 living with them, 60.20% were married couples living together, 7.70% had a female householder with no husband present, and 29.00% were non-families. 25.80% of all households were made up of individuals, and 11.60% had someone living alone who was 65 years of age or older. The average household size was 2.50 and the average family size was 3.00.

In the county, the population was spread out, with 26.00% under the age of 18, 9.10% from 18 to 24, 26.50% from 25 to 44, 21.60% from 45 to 64, and 16.80% who were 65 years of age or older. The median age was 38 years. For every 100 females, there were 94.50 males. For every 100 females age 18 and over, there were 91.60 males.

The median income for a household in the county was $40,907, and the median income for a family was $48,793. Males had a median income of $35,037 versus $22,492 for females. The per capita income for the county was $18,715. About 4.20% of families and 6.40% of the population were below the poverty line, including 7.50% of those under age 18 and 5.00% of those age 65 or over.

Presidential elections

Laws

Following amendment to the Kansas Constitution in 1986, the county remained a prohibition, or "dry", county until 1996, when voters approved the sale of alcoholic liquor by the individual drink with a 30% food sales requirement.^[13]

The county voted "No" on the 2022 Kansas Value Them Both Amendment, an anti-abortion ballot measure, by 53% to 47% despite backing Donald Trump with 59% of the vote to Joe Biden's 39% in the 2020 presidential election.^[14]

Colleges

• Bethel College in North Newton
• Hesston College in Hesston

Unified school districts

• Burrton USD 369
• Newton USD 373
• Sedgwick USD 439
• Halstead–Bentley USD 440
• Hesston USD 460

School district office in neighboring county

• Remington USD 206
• Peabody–Burns USD 398
• Goessel USD 411
• Moundridge USD 423

Cities

‡ means a community has portions in an adjacent county.

Unincorporated communities

• McLain
• Patterson
• Putnam
• Zimmerdale

Ghost towns

• Annelly
• Van Arsdale

Townships

Harvey County is divided into fifteen townships. The cities of Halstead and Newton are considered governmentally independent and are excluded from the census figures for the townships. In the following table, the population center is the largest city (or cities) included in that township's population total, if it is of a significant size.