The Ten Most Populated Counties In The United States

The United States is an enormous country filled with vastly different geographical regions, and bordered by the earth’s two largest oceans on either side. At nearly 3.8 million square miles, it is the third largest country in the world, with only Canada and Russia being larger. 

But the gigantic size of the United States doesn’t mean that its citizens are distributed evenly across its land mass. There are large parts of the country that are sparsely populated, and others that contain a much higher population density of US citizens. 

The 50 states that make up the United States are themselves divided further into 3,144 counties, administrative subregions that encompass the towns and cities in the geographical area where they are located. 

Amazingly, of the 340 million people that live in the United States, 41 million live in just ten counties. This means that 12% of the country’s population live on less than 1% of its land. To find out which counties make up the United States’ten most populous, read more below.

Our countdown begins in Southern California’s Riverside County, located just east of Los Angeles. Riverside County is the second largest county by area on this list and stretches across a large area of desert wilderness.

Found within its borders, are some of the most sacred and beautiful natural areas in the country such as Joshua Tree National Park and the Coachella Valley.

Population – 2.61 Million +
Area – 97 square miles
Largest City – Brooklyn, New York

The smallest county in terms of area on this list is also the most densely populated. Kings County, New York is one of the five counties found within New York City.

The borough of Brooklyn constitutes all of Kings County, and is the most populous of New York’s five boroughs.

Population – 2.65 Million+
Area – 908.6 square miles
Largest City – Dallas, Texas

Next up is Dallas County, located in the heart of North Texas. Dallas County is where Texas’ third largest city, the eponymous city of Dallas is found.

Dallas County is the core of the Dallas-Fort Worth-Arlington metropolitan area, the fourth largest metropolitan area in the United States.

Population – 2.83 Million+
Area – 2,431 square miles
Largest City – Miami, Florida

Number seven on the list is Miami-Dade County, the crown jewel of the South Florida Metropolitan area.

Miami-Dade County is not only the most populous in the southeastern United States, but also holds the distinction of being the most populous county with a majority Hispanic population.

Population – 3.1 Million
Area – 948 square miles
Largest City – Anaheim, California

Returning to Southern California is where we will find the country’s sixth most populous county, Orange County. Orange County is an important centerpiece of the Los Angeles Metro area, and is home to everything from beautiful beaches and theme parks, to high wealth suburbs and corporate office parks.

Population – 3.29 Million
Area – 4,260 square miles
Largest City – San Diego, California

South of Orange County is San Diego County, with a population just shy of 3.3 million people. The ocean side city of San Diego is of course found here, along with some of California’s most beautiful natural landscapes.

Population – 4.4 Million+
Area – 9,224 square miles
Largest City – Phoenix, Arizona

Another county in the Western United States is the country’s 4th most populous, Maricopa County. Anchored by the city of Phoenix, Maricopa County somehow manages to retain its large population within a region covered primarily by desert lands.

Of the ten most populous counties in the US, Maricopa County is the largest by land area, taking up a geographical region that is larger than four US states.

Population – 4.7 Million+
Area – 1,777 square miles
Largest City – Houston, Texas

The first county to break into the the top three most populous is Harris County, Texas where the sprawling city of Houston is located. Harris County has seen massive population growth over the past few years, and has become a popular destination for domestic moves within the US.

Population – 5.2 Million
Area – 1,635 square miles
Largest City – Chicago

The second largest county on the list, and the only one found in the Midwestern United States is Cook County, home to the city of Chicago. Cook County is a highly urbanized county, and is also home to nearly 40% of Illinois residents.

Population – 9.7 Million
Area – 1,635 square miles
Largest City – Los Angeles, California

Holding the number one spot is yet another Southern California powerhouse, Los Angeles County. LA County is dominated by the city of Los Angeles, the United States’ third largest city and the cultural capital of SoCal.

Los Angeles County’s population of nearly 10 million people is larger than that of 40 individual states, and is near the population of the ten least populous states combined.