One Austin neighbor is among the richest counties in Texas, according to data analysis compiled by Stacker. The website compiled a list of the wealthiest counties in Texas based on median household income, and Williamson County nabbed the No. 5 spot at $87,337.

Rockwall County in the DFW area came out on top at $100,920 — the only county in Texas to break the $100,000 mark.

The continuing influx of people into Williamson County is helping drive up the median household income.

Williamson County's population rose by 27,760 additional residents from July 2020 to July 2021, putting it at No. 5 among counties picking up the most new residents. Some of the population boom stems from East and West coast transplants fleeing higher-priced locales.

Additionally, residents of Williamson County are highly educated, which contributes to their earning power. As of 2020, 95.2% percent of the county’s residents 25 and over had graduated from high school, and nearly 61 percent of residents 25 and over had earned at least a bachelor’s degree. Both of those figures are well above the statewide numbers.

There’s also the livability factor. Georgetown, the biggest city in Williamson County, earned No. 63 on SmartAssset's recent list of the best small cities in the U.S. — which almost certainly adds to the county’s allure for high-income households.

To come up with its list, Stacker used U.S. Census Bureau data from 2019 showing the five-year estimate for median household income in each of Texas’ 254 counties. Aside from Williamson County, three other counties in the Austin area made Stacker’s list of the 50 richest counties in Texas. The other counties, followed by their median household income, are:

Austin

• No. 18 Travis County, $75,887
• No. 29 Hays County, $68,717
• No. 36 Bastrop County, $64,597

By comparison, the median household income for all of the U.S. was $68,703.

Among the state’s four major metro areas, DFW dominated in terms of the number of rich counties in Texas’ top 50. It’s worth noting, though, that DFW has more counties (11) than any other metro in Texas.

Here’s how the state’s three other major metros fared in the Stacker rankings for highest median household income by county.

Dallas-Fort Worth

• No. 3 Collin County, $96,913
• No. 6 Denton County, $86,913
• No. 14 Parker County, $77,503
• No. 15 Ellis County, $76,871
• No. 26 Kaufman County, $70,107
• No. 31 Tarrant County, $67,700
• No. 38 Wise County, $64,536
• No. 39 Johnson County, $64,359
• No. 40 Hood County, $64,041

Houston

• No. 2 Fort Bend County, $97,743
• No. 4 Chambers County, $91,141
• No. 9 Brazoria County, $81,447
• No. 10 Montgomery County, $80,902
• No. 22 Galveston County, $73,330
• No. 34 Austin County, $66,206
• No. 48 Harris County, $61,705

San Antonio

• No. 7 Kendall County, $84,747
• No. 11 Comal County, $79,936
• No. 16 Wilson County, $76,692
• No. 21 Guadalupe County, $74,496
• No. 46 Medina County, $62,599