Most Populous U.S. Counties

Name the counties of U.S. states that have the largest populations.
2019 U.S. Census estimates
Quiz by Quizmaster
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Last updated: April 18, 2020
First submittedJanuary 23, 2012
Times taken13,139
Rating3.93
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State
Population
County
California
10,039,107
Los Angeles
Illinois
5,150,233
Cook
Texas
4,713,325
Harris
Arizona
4,485,414
Maricopa
California
3,338,330
San Diego
California
3,175,692
Orange
Florida
2,716,940
Miami-Dade
Texas
2,635,516
Dallas
New York
2,559,903
Kings
California
2,470,546
Riverside
Nevada
2,266,715
Clark
New York
2,253,858
Queens
Washington
2,252,782
King
California
2,180,085
San Bernardino
Texas
2,102,515
Tarrant
Texas
2,003,554
Bexar
Florida
1,952,778
Broward
California
1,927,852
Santa Clara
Michigan
1,749,343
Wayne
California
1,671,329
Alameda
New York
1,628,706
New York
Massachusetts
1,611,699
Middlesex
Pennsylvania
1,584,064
Philadelphia
California
1,552,058
Sacramento
Florida
1,496,770
Palm Beach
State
Population
County
New York
1,476,601
Suffolk
Florida
1,471,968
Hillsborough
New York
1,418,207
Bronx
Florida
1,393,452
Orange
New York
1,356,924
Nassau
Ohio
1,316,756
Franklin
Texas
1,273,954
Travis
Minnesota
1,265,843
Hennepin
Michigan
1,257,584
Oakland
Ohio
1,235,072
Cuyahoga
Pennsylvania
1,216,045
Allegheny
Utah
1,160,437
Salt Lake
California
1,153,526
Contra Costa
Virginia
1,147,532
Fairfax
North Carolina
1,111,761
Wake
North Carolina
1,110,356
Mecklenburg
Georgia
1,063,937
Fulton
Maryland
1,050,688
Montgomery
Arizona
1,047,279
Pima
Texas
1,034,730
Collin
California
999,101
Fresno
Missouri
994,205
St. Louis
Florida
974,996
Pinellas
Hawaii
974,563
Honolulu
New York
967,506
Westchester
+4
Level ∞
Apr 18, 2020
With the latest update, we've seen major declines in all the countries in and around New York City. I guess you can't just raise rent to infinity with no consequences forever.
+7
Level 80
Jan 23, 2012
How many people typed Kings for Brooklyn, got Seattle's King instead, and never went back to Brooklyn? Guilty!!
+8
Level ∞
Jan 23, 2012
Interesting fact. Seattle's King county was once named after a guy who many people considered to be a jerk. A few years back they "renamed" the county after Martin Luther King, Jr.
+2
Level 83
Jul 6, 2018
That is interesting.
+2
Level 83
Jul 6, 2018
Seriously, I'm the only one in 6 years?
+6
Level 85
Jun 13, 2020
Only one who what? Commented directly to the Quizmaster? Why is that important?
+2
Level 54
Aug 10, 2013
I did that.
+2
Level 74
Jun 30, 2014
... and some of us (eg me) typed in King for Seattle and didn't expect NYC to have one too.
+2
Level 89
Jan 28, 2015
The stats seem to bear that out. King, Queens and the Bronx are all right there together (King slightly higher for those who know Seattle), but Kings 10% lower than the Bronx. Could also be because Kings isn't one of the Boroughs, and thus slightly less known, but that's why I missed it.
+2
Level 80
May 21, 2018
Are you saying Kings County, NY isn't a borough? It's the county that Brooklyn is coterminous with!
+4
Level 82
Sep 29, 2018
Just try typing in "Kings" on a "Name the Five Boroughs" quiz and see what happens ;)
+2
Level 26
Apr 28, 2015
yep
+2
Level 78
Sep 29, 2018
I did that.
+2
Level 70
Jun 13, 2020
I did too. I didn't think to go back because sometimes these quizzes fill in the answer without typing the "s".
+2
Level 66
Sep 21, 2014
DuPage county in Illinois has nearly one million, if not more
+5
Level ∞
Jan 28, 2015
Stop trying to discredit our American census bureau Kim!
+4
Level 66
Mar 3, 2015
Don't call me Kim, I'm not Kim! Why would I have this username if I were him...
+2
Level 74
May 22, 2018
KIm, I'd probably call myself who I am, otherwise people will just call me Kim.
+3
Level 68
Sep 29, 2018
Thinking of Ray Jay Johnson Jr. Anyone remember him?
+2
Level 78
Sep 29, 2018
You can call me Ray, you can call me Jay...
+2
Level 70
Jun 13, 2020
You can call me Ray, you can call me Jay, just don't call me too early in the day!
+2
Level 70
Jan 29, 2015
Isn't Fairfax County in Virginia? I don't recall there being a Fairfax County in Maryland. It's Prince George's and Montgomery County that borders DC on the Maryland side.
+2
Level ∞
Jan 29, 2015
Fixed
+2
Level 80
Apr 27, 2015
Comparing the "QuickFacts" from the US Census and Wikipedia, it looks like the Fairfax County number includes Fairfax (city), which is technically incorrect. Larger cites in Virginia, of which Fairfax City is an example, are independent, and for most purposes are considered county equivalents.
+2
Level 74
Apr 26, 2015
One detail, from someone who has worked as a census counter: The final figure is only accurate to within about 1%, ie 10,000 people per million - your quota is to reach over 95% of each subdistrict, after which it's not cost-effective to keep knocking on doors, and extrapolation happens after that. So when you see numbers like 10,017,368 for LA county, that figure is actually plus or minus 100,000! It's bloody ridiculous for countries' statistics departments to announce numbers to the last digit, faking an accuracy that doesn't exist.
+2
Level ∞
May 19, 2018
They do publish certainty estimates as well if you care.
+2
Level 74
May 21, 2018
I just spent a while trawling through the census.gov website for this, and couldn't find anything - do you have the link to the certainty estimates?
+2
Level ∞
Apr 18, 2020
Can't find them for counties right now. Probably have to use the API, which they are always mucking with. I know they exist though.
+3
Level 64
Apr 27, 2015
Oof, this quiz kicked my ass. I'm gonna have to bone up on this.
+2
Level 21
Oct 14, 2015
I kept trying Queen, Queen, Queen! Yet the whole time I only needed to add an S.
+2
Level 76
Sep 6, 2016
I think primary season has drastically enhanced my knowledge of US counties, with most results being reported by county.
+2
Level 78
Sep 29, 2018
Same here. "Waiting for the returns from..."
+2
Level 57
May 13, 2020
Yay my county is here!
+2
Level 66
Jun 13, 2020
+3
Level 57
Jun 13, 2020
OK not being American really held me back here, I’ve never heard of most of these (unlike states and cities)
+4
Level 70
Jun 13, 2020
That's okay. Most of us haven't really heard of the counties...just the cities, which made it an interesting quiz.
+2
Level 81
Jun 13, 2020
To infinity... and beyond!
+2
Level 63
Jun 13, 2020
40/50. I couldn't type "Montgomery" fast enough in the end.
+2
Level 73
Jan 28, 2021
Watching election coverage really helped me with this quiz.