Lancaster County is a county located in the U.S. state of Nebraska. As of the 2020 United States Census, the population was 322,608, making it the second-most populous county in Nebraska. Its county seat is Lincoln, the state capital. The county was created in 1859.

Lancaster County is part of the Lincoln, NE Metropolitan Statistical Area.

In the Nebraska license plate system, Lancaster County was represented by the prefix 2 (it had the second-largest number of vehicles registered in the state when the license plate system was established in 1922). In 2002, the state discontinued the 1922 system in Lancaster, Douglas and Sarpy counties.

According to the US Census Bureau, the county has a total area of 846 square miles (2,190 km), of which 838 square miles (2,170 km) is land and 8.8 square miles (23 km) (1.0%) is water.

• Amtrak California Zephyr (Lincoln station)
• Burlington Trailways
• Express Arrow
• StarTran

In 2004, Lancaster County was named a StormReady county by the National Weather Service.

Historical population

Census	Pop.	Note	%±
1860	153		—
1870	7,074		4,523.5%
1880	28,090		297.1%
1890	76,395		172.0%
1900	64,835		−15.1%
1910	73,793		13.8%
1920	85,902		16.4%
1930	100,324		16.8%
1940	100,585		0.3%
1950	119,742		19.0%
1960	155,272		29.7%
1970	167,972		8.2%
1980	192,884		14.8%
1990	213,641		10.8%
2000	250,291		17.2%
2010	285,407		14.0%
2020	322,608		13.0%
2023 (est.)	326,716		1.3%
US Decennial Census 1790–1960 1900–1990 1990–2000 2010

As of the 2020 United States Census, there were 322,608 people in the county. The population density was 381 people per square mile (147 people/km). The racial makeup of the county was 79.7% White, 4.5% Black or African American, 1.0% Native American, 4.7% Asian American, 0.1% Pacific Islander, and 3.3% from two or more races. 8.1% of the population were Hispanic or Latino of any race.

As of the 2000 United States Census, there were 250,291 people, 99,187 households, and 60,702 families in the county. The population density was 298 people per square mile (115 people/km). There were 104,217 housing units at an average density of 124 per square mile (48/km). The racial makeup of the county was 90.07% White, 2.82% Black or African American, 0.64% Native American, 2.86% Asian American, 0.06% Pacific Islander, 1.69% from other races, and 1.87% from two or more races. 3.37% of the population were Hispanic or Latino of any race. 39.1% were of German, 7.9% English and 7.8% Irish ancestry.

There were 99,187 households, out of which 30.30% had children under the age of 18 living with them, 48.80% were married couples living together, 9.10% had a female householder with no husband present, and 38.80% were non-families. 29.10% of all households were made up of individuals, and 8.30% had someone living alone who was 65 years of age or older. The average household size was 2.40 and the average family size was 3.00.

The county population contained 23.50% under the age of 18, 15.40% from 18 to 24, 30.40% from 25 to 44, 20.30% from 45 to 64, and 10.40% who were 65 years of age or older. The median age was 32 years. For every 100 females, there were 99.80 males. For every 100 females age 18 and over, there were 98.50 males.

The median income for a household in the county was $41,850, and the median income for a family was $53,676. Males had a median income of $34,720 versus $25,614 for females. The per capita income for the county was $21,265. About 5.50% of families and 9.50% of the population were below the poverty line, including 9.90% of those under age 18 and 6.10% of those age 65 or over.

• Bennet
• Hickman
• Lincoln (county seat)
• Waverly

• Agnew
• Cheney
• Emerald
• Kramer
• Martell
• Prairie Home
• Princeton
• Walton
• Yankee Hill

Lancaster County is divided into the following census divisions called precincts, defined by the boundaries of the original townships, except for the City of Lincoln.

Lancaster County has historically been somewhat conservative for an urban county. In the last 30 national elections, Lancaster County selected the Republican Party candidate 78% of the time. However, it has become more competitive in recent years, largely due to the influence of Lincoln and the University of Nebraska. Since 1988, the margin in the county has been 10 points or less all but once. In 2008, Barack Obama won a narrow majority in Lancaster County, becoming the first Democrat to carry the county since 1964, and only the second since 1936. The county gave a narrow plurality to Hillary Clinton in 2016, winning the county by just 310 votes and a 0.23% margin.

As of January 2024, Republicans maintain a relative advantage in party registration in the county.

Registered voters by party in Lancaster County on January 1, 2024

Republican	Democratic	Libertarian	Non-Partisan	Total
79,855 (39.84%)	68,660 (34.25%)	3,316 (1.65%)	48,605 (24.25%)	200,436 (100%)

United States presidential election results for Lancaster County, Nebraska

Year	Republican		Democratic		Third party(ies)
	No.	%	No.	%	No.	%
2024	74,215	46.75%	81,012	51.04%	3,507	2.21%
2020	70,092	44.58%	82,293	52.34%	4,830	3.07%
2016	61,588	45.21%	61,898	45.44%	12,737	9.35%
2012	62,434	49.02%	62,015	48.69%	2,906	2.28%
2008	59,398	46.59%	65,734	51.56%	2,358	1.85%
2004	69,764	56.03%	52,747	42.36%	1,998	1.60%
2000	55,514	51.82%	44,650	41.68%	6,968	6.50%
1996	44,812	45.86%	43,339	44.36%	9,557	9.78%
1992	41,590	39.46%	41,402	39.28%	22,407	21.26%
1988	44,744	49.87%	44,396	49.48%	583	0.65%
1984	48,778	59.31%	32,898	40.00%	569	0.69%
1980	38,780	50.87%	27,162	35.63%	10,291	13.50%
1976	39,041	56.47%	28,301	40.94%	1,789	2.59%
1972	42,573	62.15%	25,924	37.85%	0	0.00%
1968	33,051	55.52%	23,539	39.54%	2,940	4.94%
1964	23,887	40.91%	34,503	59.09%	0	0.00%
1960	37,725	62.57%	22,564	37.43%	0	0.00%
1956	35,591	64.94%	19,217	35.06%	0	0.00%
1952	36,797	67.49%	17,728	32.51%	0	0.00%
1948	23,620	56.29%	18,338	43.71%	0	0.00%
1944	26,715	58.01%	19,338	41.99%	0	0.00%
1940	27,384	58.63%	19,321	41.37%	0	0.00%
1936	20,902	47.39%	22,366	50.71%	838	1.90%
1932	20,772	52.29%	18,190	45.79%	761	1.92%
1928	30,523	75.17%	9,840	24.23%	242	0.60%
1924	18,061	54.40%	11,563	34.83%	3,575	10.77%
1920	15,638	62.58%	8,435	33.75%	917	3.67%
1916	7,042	42.20%	9,093	54.49%	553	3.31%
1912	2,566	18.16%	6,708	47.47%	4,857	34.37%
1908	7,428	45.15%	8,540	51.91%	485	2.95%
1904	8,167	70.77%	1,981	17.16%	1,393	12.07%
1900	7,465	55.27%	5,677	42.03%	365	2.70%
1896	6,513	52.17%	5,687	45.55%	284	2.27%
1892	5,858	52.69%	1,283	11.54%	3,977	35.77%
1888	5,677	56.97%	3,508	35.20%	780	7.83%
1884	4,011	62.69%	2,180	34.07%	207	3.24%
1880	3,397	69.50%	1,381	28.25%	110	2.25%

• Roma Amundson, District 4 Commissioner, retired U.S. Brigadier General

School districts include:

• National Register of Historic Places listings in Lancaster County, Nebraska

• Leon Riley (1906–1970), American minor league baseball player/manager (born in Princeton, Nebraska).

• Lancaster County, Nebraska
• University of Nebraska-Lincoln Extension in Lancaster County

40°47′N 96°41′W / 40.78°N 96.69°W / 40.78; -96.69