Mertzon, Texas

As of the 2020 United States census, there were 747 people, 356 households, and 264 families residing in the city.

As of the census[3] of 2000, 839 people, 315 households, and 239 families resided in the city. The population density was 551.4 inhabitants per square mile (212.9/km²). There were 364 housing units at an average density of 239.2 per square mile (92.4/km²). The racial makeup of the city was 85.22% White, 0.60% African American, 0.36% Native American, 11.68% from other races, and 2.15% from two or more races. Hispanics or Latinos of any race were 34.21% of the population.

Of the 315 households, 34.0% had children under the age of 18 living with them, 61.9% were married couples living together, 9.2% had a female householder with no husband present, and 24.1% were not families. About 21.3% of all households were made up of individuals, and 12.1% had someone living alone who was 65 years of age or older. The average household size was 2.66 and the average family size was 3.09.

In the city, the population was distributed as 28.8% under the age of 18, 6.2% from 18 to 24, 27.4% from 25 to 44, 22.4% from 45 to 64, and 15.1% who were 65 years of age or older. The median age was 37 years. For every 100 females, there were 95.6 males. For every 100 females age 18 and over, there were 95.7 males.

The median income for a household in the city was $33,333, and for a family was $40,417. Males had a median income of $33,438 versus $17,250 for females. The per capita income for the city was $17,795. About 8.9% of families and 9.6% of the population were below the poverty line, including 8.4% of those under age 18 and 11.7% of those age 65 or over.