The Richest Counties In The United States

Prosperity has a geography, and some American counties are leading the pack. In all 50 states, there are 3,144 counties or equivalent jurisdictions, but only some manage to stand out as the richest with their fast growth and consistent innovation. With examples of excellence in the hyper-connected data hub in Loudoun County, VA, or the vital healthcare ecosystem based in Marin County, CA, it is clear that these counties' achievements are truly remarkable. Now read on to learn which regions possess "America's Richest Counties," according to each county's median annual household income. All data is from the U.S. Census Bureau.

Top 10 Richest United States Counties

Click here for a table of the top 30 richest counties in the United States

1. Loudoun County, Virginia - $156,821

Loudoun County is home to the world's largest and fastest-growing data center hub. Prominent industry leaders like Amazon, Verizon Business, Google, Facebook, and Salesforce all trust their most important digital assets to the connectivity in this hyper-connected county. It receives more than $9.50 in tax revenue for every dollar invested into data centers, helping schools and public safety personnel. Regarding population, 420,959 people of the Commonwealth of Virginia call Loudoun County home and actively contribute to its growing economy. Additionally, Loudoun County takes full advantage of the craft beverage revolution, with more than 40 wineries and more than 30 breweries, exceeding any other county in the state. With a median household income of $156,821, Loudoun County is the richest jurisdiction in the United States.

2. Falls Church, Virginia - $155,071

Falls Church is an independent city that has county-level governance status with a population of 14,658 people and a median household income of $155,071. The township of Falls Church is the second richest jurisdiction in Virginia and the United States. While Fortune 500 companies General Dynamics and Northrop Grumman have headquarters with mailing addresses in Falls Church, they are physically in Fairfax County. Still, government jobs are prominent here, and other top employers include the Falls Church City Public Schools, healthcare giant Kaiser Permanente, management, finance, and systems engineering firm Markon Solutions, and the automotive dealership Koons Ford. Despite its small size, Falls Church stands out as one of the healthiest economies in the U.S.

3. Santa Clara County, California - $140,258

Santa Clara County is a vital part of one of California's busiest urban areas-the San Francisco Bay Area. With an enormous population of 1,936,259, its citizens managed to achieve an impressively high median household income of $140,258 and reach the podium of the richest counties in the United States. The city of Santa Clara is the focal point of the county in the heart of Silicon Valley, with its many tech giants employing large amounts of the workforce. It is home to hugely famous and renowned companies like Apple, Intel, and Oracle that, united with numerous start-ups, make this county a hotbed for innovation.

4. San Mateo County, California - $136,837

San Mateo County is one of nine counties that significantly contributes to the economy of the San Francisco Bay Area and is the second most prosperous in California and fourth in the United States. The coastal Santa Cruz Mountain range bisects San Mateo County, leaving the western side to more rural uses such as agriculture, hunting preserves, watersheds, parks, and undeveloped lands. In contrast, the much more densely populated eastern half of the county contains most major transportation arteries and facilities, including the Dumbarton and San Mateo Bridges, and going as far as the San Francisco International Airport and the prominent port of Redwood City. High-paying jobs in finance, science, and health care make the San Mateo County median household income $136,837.

5. Fairfax County, Virginia - $133,974

Fairfax County has exceptional economic growth, and its 1,150,309 people are working to ensure continued success. With a median household income of $133,974, Fairfax offers a high quality of life, but the cost of living is famously steep. Some major companies with locations in Fairfax include Paycom, Apple Inc., and Amazon Web Services. Other large employers include General Dynamics and Northrop Grumman, thanks to large government contracts. For example, the Reston-based company Leidos was selected by the U.S. Army to train pilots who will be part of the High Accuracy Detection program. Additionally, Fairfax County's economy is supported by the Fairfax County Economic Development Authority, which helps and promotes Fairfax County as a leading business and technology center and contributes to the overall success of the state of Virginia.

6. Marin County, California - $131,008

Marin County's breathtaking natural scenery and vistas of the Pacific Ocean attract many visitors every year, making Tourism play a significant role in Marin's economy. With an average two-bedroom rent cost of $3,190, remarkably higher than the U.S. average of $1,430, Marin County's higher quality of life comes at a steep price. Local companies in Marin, such as Marin Clean Energy, Marin Organic, and Whole Foods, provide organic food options, renewable energy solutions, and more. Marin County has been fortunate to have a prosperous economy within the broader San Francisco Bay Area. So, tech and healthcare giants from Silicon Valley spill over into Marin County to provide a high salary that brings the county median household income to $131,008, which is the third highest in California and sixth in the United States.

7. Howard County, Maryland - $129,549

Howard County is one of the country's healthiest communities, centrally located between two of the most populous metropolitan areas in Maryland, Washington, D.C., and Baltimore. Howard County is at the center of the growing cybersecurity industry due to its proximity to the U.S. Cyber Command, Fort George Meade, and the National Security Agency. The county is also home to major research institutions like Johns Hopkins Applied Physics Lab and companies like Merkle, W.R. Grace, Tenable Network Security, Medstar, and Maxim Healthcare Services. Howard County's strategic location, strong employment base, enviable quality of life, and superior suburban setting position grant it $28.8 billion in economic output and get the median household income to $129,549, the seventh in the United States.

8. Arlington County, Virginia - $128,145

Arlington County has consistently had the lowest unemployment rate of any jurisdiction in Virginia, with only 1.9%. There are many well-known companies located in Arlington County, such as Nestle USA, Amazon, Deloitte, Capital One, and Lockheed Martin. Moreover, many federal agencies are headquartered in Arlington County, including the Air Force Office of Scientific Research, DARPA, United States Department of Defense, Nuclear Waste Technical Review Board, and many more, employing large amounts of the workforce. With its growing economy and affordable amenities, it is no wonder why so many people choose to call Arlington County home. With a population of 238,643 people and a median household income of $128,145, Arlington is fourth in Virginia and the eighth wealthiest county in the United States.

9. Douglas County, Colorado - $127,443

Douglas County has been acknowledged by a number of national periodicals as one of the healthiest economies in the country and for its notable quality of life. With its median household income of $127,443, Douglas County ranks as the ninth richest county in the United States. The major employer is the Douglas County School District, which comprises around 30% of the workers. Other top employers include the large banking corporation Charles Schwab, big telecommunications player EchoStar, engineering company CH2M, and healthcare giant HealthONE, among many others. Besides, the community of 357,978 hard-working people is the reason for Douglas County's recognition as the richest in Colorado. 

10. Nassau County, New York - $126,576

Nassau County has an abundance of local businesses and hosts a range of companies, such as L&L Manufacturing Company, Five Star Home Care, Karp Associates Inc., and Cardillo Worldwide Logistics. These businesses provide jobs and services that are vital to the local economy and are highly valued by citizens in Nassau County. The median household is $126,576, making it the richest county in New York, entering the top ten in the United States. The educated workforce and high quality of life, low crime, and excellent schools, as well as the county's proximity to New York City, are some of the assets that Nassau County has at its disposal. With a positive trend to this county's growth, we might see Nassau County get higher on the list in the upcoming years.

The communities that form these outstanding counties are the lifeblood of the United States and one of the biggest reasons for its large economy. Without easy access to higher-income jobs, these hard-working people's education played a crucial role in their success. As the ten richest jurisdictions, these counties have shown an extraordinary will to strive for the top spots. With the constant investments of government agencies and giant corporations, these counties are predicted to boom even more in the foreseeable future.

Top 30 Richest Counties In The United States