The 100 Largest Counties in the United States

Los Angeles County, CA is by far the largest county in America: its 9,808,667 residents outnumber the populations of 40 individual states. Nationwide, 48 counties top one million residents. This page ranks the 100 most populous of the country's 3,144 counties and county equivalents.

Top 10 US Counties by Population

Los Angeles, CA

9.8M

Cook, IL

5.2M

Harris, TX

4.8M

Maricopa, AZ

4.6M

San Diego, CA

3.3M

Orange, CA

3.2M

Miami-Dade, FL

2.7M

Kings, NY

2.6M

Dallas, TX

2.6M

Riverside, CA

2.5M

County population says more about how states draw their maps than about how many people live nearby. California places 15 counties in the top 100 partly because it organizes its huge metros into a few sprawling counties, while East Coast states split similar metros across many small ones — which is why Los Angeles County and Cook County dwarf famous urban counties elsewhere. Texas, with 254 counties, slices its population thinner than any other state.

Because these counties contain whole metro economies, their demographics converge toward the national profile: big counties mix affluent suburbs and poor neighborhoods into medians that rarely stand out on the richest counties list. The truly distinctive demographics live at the city level — see the 100 largest cities for the municipal version of this list, where boundaries make the comparison sharper.

Full Rankings

#	County	Population	Median Income	Median Age	Poverty
1	Los Angeles County, CA	9,808,667	$90,112	38.2 years	13.7%
2	Cook County, IL	5,182,090	$83,498	38.0 years	13.5%
3	Harris County, TX	4,838,303	$74,983	34.6 years	16.3%
4	Maricopa County, AZ	4,559,748	$89,300	37.6 years	11.0%
5	San Diego County, CA	3,288,774	$106,268	37.3 years	10.3%
6	Orange County, CA	3,165,820	$116,289	39.4 years	9.5%
7	Miami-Dade County, FL	2,738,356	$71,753	40.7 years	14.7%
8	Kings County, NY	2,631,580	$80,263	36.5 years	19.1%
9	Dallas County, TX	2,621,179	$76,547	34.1 years	13.9%
10	Riverside County, CA	2,478,600	$93,074	37.0 years	10.6%
11	Clark County, NV	2,329,548	$76,472	38.5 years	13.0%
12	Queens County, NY	2,323,052	$86,136	40.7 years	12.9%
13	King County, WA	2,287,171	$124,746	37.4 years	8.6%
14	San Bernardino County, CA	2,197,104	$85,478	34.7 years	13.4%
15	Tarrant County, TX	2,167,390	$84,207	35.2 years	11.1%
16	Bexar County, TX	2,067,341	$72,341	34.8 years	14.6%
17	Broward County, FL	1,977,129	$77,633	41.3 years	12.2%
18	Santa Clara County, CA	1,902,047	$164,281	38.1 years	7.1%
19	Wayne County, MI	1,772,259	$60,539	37.9 years	20.8%
20	Alameda County, CA	1,649,473	$129,367	39.0 years	9.2%
21	Middlesex County, MA	1,638,365	$130,847	38.9 years	7.7%
22	New York County, NY	1,629,477	$103,931	38.9 years	16.5%
23	Sacramento County, CA	1,594,006	$92,175	37.5 years	12.5%
24	Philadelphia County, PA	1,579,706	$61,953	35.3 years	21.4%
25	Palm Beach County, FL	1,533,806	$83,581	45.3 years	11.3%
26	Suffolk County, NY	1,530,146	$130,686	41.7 years	6.4%
27	Hillsborough County, FL	1,522,748	$79,540	37.9 years	12.7%
28	Orange County, FL	1,471,937	$79,719	36.6 years	13.0%
29	Bronx County, NY	1,404,779	$48,676	36.0 years	27.8%
30	Nassau County, NY	1,389,591	$146,202	42.0 years	5.4%
31	Franklin County, OH	1,333,048	$75,176	34.8 years	14.7%
32	Travis County, TX	1,330,015	$99,611	35.6 years	10.9%
33	Oakland County, MI	1,279,825	$97,760	41.3 years	7.7%
34	Hennepin County, MN	1,269,496	$97,653	37.6 years	10.0%
35	Cuyahoga County, OH	1,245,873	$64,468	40.4 years	16.1%
36	Allegheny County, PA	1,238,177	$78,548	40.6 years	11.5%
37	Salt Lake County, UT	1,196,523	$97,494	34.0 years	8.1%
38	Wake County, NC	1,178,653	$105,768	37.3 years	8.1%
39	Contra Costa County, CA	1,165,012	$127,229	40.5 years	8.4%
40	Collin County, TX	1,163,337	$121,600	37.3 years	6.2%
41	Mecklenburg County, NC	1,154,681	$87,005	35.5 years	10.4%
42	Fairfax County, VA	1,147,837	$153,637	39.1 years	5.9%
43	Fulton County, GA	1,076,561	$95,292	36.4 years	12.3%
44	Montgomery County, MD	1,065,949	$132,450	40.2 years	7.4%
45	Pima County, AZ	1,060,490	$70,315	39.8 years	14.3%
46	Duval County, FL	1,023,153	$71,277	36.9 years	14.1%
47	Fresno County, CA	1,016,725	$74,201	33.5 years	18.3%
48	Honolulu County, HI	1,001,146	$106,195	39.8 years	9.2%
49	Westchester County, NY	999,677	$118,976	41.8 years	9.0%
50	St. Louis County, MO	995,569	$82,936	40.3 years	9.8%
51	Gwinnett County, GA	979,864	$87,890	36.0 years	10.8%
52	Denton County, TX	979,561	$111,498	37.0 years	7.1%
53	Capitol Planning Region, CT	977,290	$93,394	40.0 years	10.3%
54	Marion County, IN	975,809	$66,346	34.4 years	15.3%
55	Pinellas County, FL	963,481	$72,646	49.0 years	11.5%
56	Bergen County, NJ	962,316	$124,884	42.0 years	6.8%
57	Prince George's County, MD	959,754	$101,798	38.5 years	10.8%
58	Erie County, NY	950,622	$72,839	40.4 years	13.9%
59	Pierce County, WA	930,319	$99,564	37.0 years	8.8%
60	DuPage County, IL	930,024	$112,096	40.2 years	6.6%
61	Milwaukee County, WI	926,331	$64,435	35.5 years	17.2%
62	Shelby County, TN	919,173	$63,767	35.9 years	17.8%
63	Kern County, CA	915,075	$70,210	32.7 years	19.1%
64	Fort Bend County, TX	893,767	$114,041	37.3 years	7.6%
65	Hidalgo County, TX	891,977	$54,338	30.5 years	26.7%
66	Macomb County, MI	879,853	$77,837	41.3 years	10.4%
67	Middlesex County, NJ	871,290	$111,549	39.5 years	8.6%
68	El Paso County, TX	870,779	$59,806	33.6 years	18.8%
69	Worcester County, MA	867,788	$95,939	40.2 years	10.3%
70	Montgomery County, PA	867,573	$113,915	41.2 years	6.5%
71	Essex County, NJ	863,002	$80,789	37.7 years	14.6%
72	Baltimore County, MD	850,796	$91,768	39.7 years	9.8%
73	Snohomish County, WA	844,430	$111,246	38.6 years	8.0%
74	Ventura County, CA	837,469	$109,797	39.6 years	9.3%
75	Hamilton County, OH	830,774	$72,470	36.9 years	15.0%
76	San Francisco County, CA	830,235	$140,970	40.0 years	11.2%
77	Lee County, FL	817,666	$76,107	49.0 years	12.0%
78	Essex County, MA	813,054	$101,883	41.2 years	9.4%
79	Oklahoma County, OK	806,199	$66,679	35.2 years	16.0%
80	Multnomah County, OR	801,477	$88,766	38.7 years	12.6%
81	San Joaquin County, CA	797,334	$92,179	35.4 years	12.4%
82	Polk County, FL	790,694	$65,978	39.5 years	14.5%
83	Suffolk County, MA	785,121	$95,631	33.9 years	16.2%
84	Jefferson County, KY	783,022	$69,866	38.4 years	14.3%
85	Cobb County, GA	775,208	$102,738	37.5 years	8.7%
86	DeKalb County, GA	765,351	$80,644	36.4 years	13.7%
87	Monroe County, NY	753,753	$76,382	39.6 years	13.7%
88	El Paso County, CO	742,999	$90,363	35.1 years	8.5%
89	San Mateo County, CA	742,340	$158,855	40.9 years	6.7%
90	Norfolk County, MA	730,082	$130,739	40.9 years	6.7%
91	Jackson County, MO	719,976	$68,577	37.0 years	14.1%
92	Denver County, CO	718,877	$94,718	35.3 years	11.2%
93	Hudson County, NJ	718,323	$91,795	35.8 years	14.9%
94	Davidson County, TN	715,388	$77,853	34.6 years	14.0%
95	Lake County, IL	714,223	$110,416	39.1 years	8.3%
96	Utah County, UT	705,400	$100,671	25.8 years	8.7%
97	Will County, IL	701,462	$109,984	39.1 years	7.3%
98	Montgomery County, TX	684,432	$97,701	37.2 years	9.4%
99	District of Columbia, DC	681,294	$109,870	34.9 years	15.4%
100	Tulsa County, OK	680,794	$69,009	36.0 years	14.7%

Populations reflect county (or county-equivalent) boundaries from the ACS 5-Year Estimates.

Source: U.S. Census Bureau, American Community Survey (ACS) 5-Year Estimates.

About This Ranking

All figures come from the U.S. Census Bureau's American Community Survey (ACS) 5-Year Estimates, the Bureau's most reliable dataset for state and local statistics. Because estimates pool five years of survey responses, they describe a recent period rather than a single moment, and small differences between closely ranked entries may fall within the survey's margin of error. Learn more about the data on our methodology page or at data.census.gov.

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Frequently Asked Questions

What is the largest county in the US by population?

Los Angeles County in California is the largest US county with 9,808,667 residents — more than the population of 40 states. Cook County, Illinois is second at 5,182,090.

How many US counties have over 1 million residents?

48 of the country's 3,144 counties and county equivalents have more than one million residents, and together they hold a large share of the total US population.

How many counties are there in the United States?

There are 3,144 counties and county equivalents in the US, including parishes in Louisiana, boroughs and census areas in Alaska, and independent cities such as Baltimore and the cities of Virginia.