Clinton County is a county located in the U.S. state of Iowa. As of the 2020 census, the population was 46,460. Its county seat is Clinton. Its name is in honor of the seventh Governor of New York State, DeWitt Clinton. Clinton County comprises the Clinton, Iowa Micropolitan Statistical Area, which is also included in the Davenport–Moline–Clinton, Muscatine, Iowa–Illinois Combined Statistical Area.

Clinton County was formed on December 21, 1837. It was named for DeWitt Clinton, a Governor of New York and most ardent advocate for the construction of the Erie Canal. The cities of DeWitt and Clinton were also named after him.

In 1835, Elijah Buell built a log cabin for himself and his family and was thus the first settler of the region. In 1854, the first newspaper was issued and in 1858, the Lyons Female College for girls opened its doors. The tuition was set at $175 per student.

The county has used three courthouses in its history. The structure currently in use was constructed in Romanesque style and opened in 1897.

Clinton county was first settled in 1836, by Mr. Bourne, who located upon Sec. 1, T. 80, R. 4, East. The county was surveyed in 1837, by the Messrs. Burtz. The Surveyor General's office was then at Cincinnati, Ohio. In 1840, the county was organized by Sheriff Bourne. In 1841, R. R. Bed ford and others formed a little settlement at De Witt, and during the same year Messrs. Wheeler and Evans erected a log court-house. In stepping from the past to the present, we quote the language of one of the "oldest inhabitants." He says: "Clinton County was originally settled by the poorest class of people on God's earth; and it is with great pleasure that I have witnessed their progress, slow but sure, and now find the most of them very comfortably situated."

The population of this County in 1840, was 821; in 1850, 2822; in 1854, 7000; and in 1856, 11,000. The population of Lyons in 1850, was 453. In 1856 the population increased to 2700.

According to the U.S. Census Bureau, the county has a total area of 710 square miles (1,800 km), of which 695 square miles (1,800 km) is land and 15 square miles (39 km) (2.1%) is water. It includes the easternmost point in the state of Iowa, on the Mississippi River in Elk River township in the northeast section of the county.

• Clinton Municipal Transit Administration

• US 30
• US 61
• US 67
• Iowa 136

• Jackson County (north)
• Carroll County, Illinois (northeast)
• Whiteside County, Illinois (east)
• Rock Island County, Illinois (southeast)
• Scott County (south)
• Cedar County (southwest)
• Jones County (northwest)

• Upper Mississippi River National Wildlife and Fish Refuge (part)

Historical population

Census	Pop.	Note	%±
1840	821		—
1850	2,822		243.7%
1860	18,938		571.1%
1870	35,357		86.7%
1880	36,763		4.0%
1890	41,199		12.1%
1900	43,832		6.4%
1910	45,394		3.6%
1920	43,371		−4.5%
1930	44,377		2.3%
1940	44,722		0.8%
1950	49,664		11.1%
1960	55,060		10.9%
1970	56,749		3.1%
1980	57,122		0.7%
1990	51,040		−10.6%
2000	50,149		−1.7%
2010	49,116		−2.1%
2020	46,460		−5.4%
2023 (est.)	46,158		−0.7%
U.S. Decennial Census 1790-1960 1900-1990 1990-2000 2010-2018

The 2020 census recorded a population of 46,460 in the county, with a population density of 66.851/sq mi (25.8111/km). 94.95% of the population reported being of one race. There were 21,517 housing units of which 19,483 were occupied.

Clinton County Racial Composition

Race	Num.	Perc.
White (NH)	41,226	88.73%
Black or African American (NH)	1,392	3%
Native American (NH)	103	0.22%
Asian (NH)	252	0.54%
Pacific Islander (NH)	10	0.02%
Other/Mixed (NH)	1,938	4.2%
Hispanic or Latino	1,539	3.31%

The 2010 census recorded a population of 49,116 in the county, with a population density of 70.67/sq mi (27.286/km). There were 21,733 housing units, of which 20,223 were occupied.

As of the census of 2000, there were 50,149 people, 20,105 households, and 13,671 families residing in the county. The population density was 72 people per square mile (28 people/km). There were 21,585 housing units at an average density of 31 per square mile (12/km). The racial makeup of the county was 95.87% White, 1.89% Black or African American, 0.24% Native American, 0.56% Asian, 0.02% Pacific Islander, 0.34% from other races, and 1.08% from two or more races. 1.25% of the population were Hispanic or Latino of any race.

There were 20,105 households, out of which 31.80% had children under the age of 18 living with them, 54.60% were married couples living together, 9.80% had a female householder with no husband present, and 32.00% were non-families. 27.40% of all households were made up of individuals, and 12.20% 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 2.98.

In the county, the population was spread out, with 25.60% under the age of 18, 8.20% from 18 to 24, 27.00% from 25 to 44, 23.30% from 45 to 64, and 15.80% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 94.30 males. For every 100 females age 18 and over, there were 91.20 males.

The median income for a household in the county was $37,423, and the median income for a family was $46,450. Males had a median income of $35,049 versus $21,333 for females. The per capita income for the county was $17,724. About 7.70% of families and 10.20% of the population were below the poverty line, including 13.70% of those under age 18 and 7.80% of those age 65 or over.

• Big Rock (mostly in Scott County)
• Bryant
• Buena Vista
• Elvira
• Elwood
• Folletts
• Petersville
• Teeds Grove

Clinton County is divided into these townships:

The population ranking of the following table is based on the 2020 census of Clinton County. † county seat

Rank	City/Town/etc.	Municipal type	Population (2020 Census)
1	Clinton †	City	24,469
2	DeWitt	City	5,514
3	Camanche	City	4,570
4	Wheatland	City	775
5	Grand Mound	City	615
6	Delmar	City	542
7	Lost Nation	City	434
8	Charlotte	City	389
9	Calamus	City	356
10	Low Moor	City	250
11	Goose Lake	City	239
12	Welton	City	121
13	Andover	City	109
14	Toronto	City	102

Similar to many other counties in Iowa, Clinton County was reliably Democratic from Michael Dukakis's win in 1988 until 2016, when Trump flipped many counties in Iowa. He improved on his results in 2020.

United States presidential election results for Clinton County, Iowa

Year	Republican		Democratic		Third party(ies)
	No.	%	No.	%	No.	%
2020	13,361	54.12%	10,812	43.80%	514	2.08%
2016	11,276	48.88%	10,095	43.76%	1,696	7.35%
2012	9,432	37.73%	15,141	60.56%	427	1.71%
2008	9,324	37.72%	15,018	60.75%	380	1.54%
2004	10,666	43.21%	13,813	55.96%	205	0.83%
2000	9,229	41.61%	12,276	55.35%	675	3.04%
1996	7,624	35.30%	11,481	53.17%	2,490	11.53%
1992	8,746	35.04%	11,683	46.81%	4,531	18.15%
1988	10,243	44.53%	12,549	54.56%	210	0.91%
1984	13,914	54.77%	11,240	44.25%	250	0.98%
1980	13,025	51.66%	9,698	38.47%	2,488	9.87%
1976	12,401	50.55%	11,746	47.88%	387	1.58%
1972	12,768	55.60%	9,895	43.09%	301	1.31%
1968	11,513	51.92%	9,515	42.91%	1,147	5.17%
1964	8,219	36.48%	14,267	63.32%	47	0.21%
1960	13,797	56.71%	10,508	43.19%	25	0.10%
1956	14,765	63.62%	8,394	36.17%	49	0.21%
1952	15,372	65.73%	7,975	34.10%	38	0.16%
1948	9,859	52.82%	8,534	45.72%	272	1.46%
1944	11,533	58.77%	8,028	40.91%	63	0.32%
1940	12,177	54.17%	10,251	45.60%	50	0.22%
1936	10,016	43.47%	12,269	53.25%	757	3.29%
1932	9,085	41.52%	12,587	57.53%	208	0.95%
1928	12,295	58.57%	8,643	41.17%	54	0.26%
1924	10,359	52.68%	3,811	19.38%	5,495	27.94%
1920	11,746	66.98%	3,153	17.98%	2,637	15.04%
1916	5,576	56.61%	3,903	39.62%	371	3.77%
1912	1,890	20.58%	3,633	39.55%	3,662	39.87%
1908	4,836	48.68%	4,821	48.53%	277	2.79%
1904	5,265	53.23%	4,074	41.19%	552	5.58%
1900	5,344	51.19%	4,758	45.58%	337	3.23%
1896	5,584	54.02%	4,590	44.40%	163	1.58%

• National Register of Historic Places listings in Clinton County, Iowa
• Clinton County Courthouse

• Clinton County government's website
• Clinton County Development Association

41°53′34″N 90°31′39″W / 41.89278°N 90.52750°W / 41.89278; -90.52750