San Saba is a city in and the county seat of San Saba County, Texas, United States. It was settled in 1854 and named for its location on the San Saba River and for Sabbas the Sanctified. Its population was 3,099 at the 2010 census.

According to the United States Census Bureau, the city has a total area of 1.8 sq mi (4.7 km²), all land. The city is located 105 miles (169.0 km) northwest of Austin, and 141 miles (226.9 km) miles north of San Antonio.

The climate in this area is characterized by hot, humid summers and generally mild to cool winters. According to the Köppen climate classification, San Saba has a humid subtropical climate, Cfa on climate maps.

The 2020 United States census counted 3,117 people, 1,021 households, and 666 families in San Saba. The population density was 1,150.6 per square mile (444.3/km²). There were 1,209 housing units at an average density of 446.3 per square mile (172.3/km²). The racial makeup was 63.36% (1,975) white or European American (48.67% non-Hispanic white), 3.53% (110) black or African-American, 0.58% (18) Native American or Alaska Native, 0.55% (17) Asian, 0.06% (2) Pacific Islander or Native Hawaiian, 20.44% (637) from other races, and 11.49% (358) from two or more races. Hispanic or Latino of any race was 45.43% (1,416) of the population.

Of the 1,021 households, 33.3% had children under the age of 18; 42.6% were married couples living together; 31.5% had a female householder with no spouse or partner present. 30.7% of households consisted of individuals and 15.9% had someone living alone who was 65 years of age or older. The average household size was 2.5 and the average family size was 3.2. The percent of those with a bachelor's degree or higher was estimated to be 6.0% of the population.

22.2% of the population was under the age of 18, 9.0% from 18 to 24, 31.2% from 25 to 44, 21.3% from 45 to 64, and 16.3% who were 65 years of age or older. The median age was 35.3 years. For every 100 females, there were 151.6 males. For every 100 females ages 18 and older, there were 172.0 males.

The 2016-2020 5-year American Community Survey estimates show that the median household income was $31,181 (with a margin of error of +/- $5,672) and the median family income was $40,083 (+/- $10,742). Males had a median income of $26,071 (+/- $9,347) versus $15,690 (+/- $7,740) for females. The median income for those above 16 years old was $23,354 (+/- $5,715). Approximately, 14.2% of families and 20.2% of the population were below the poverty line, including 37.4% of those under the age of 18 and 8.7% of those ages 65 or over.

As of the census of 2010, 3,099 people, 1,008 households, and 680 families resided in the city. The population density was 1,468.6 people/sq mi (565.6/km²). The 1,177 housing units averaged 655.5/sq mi (252.5/km²). The racial makeup of the city was 78.54% White, 0.64% African American, 1.74% Native American, 0.11% Asian, 17.33% from other races, and 1.63% from two or more races. Hispanics or Latinos of any race were 31.51% of the population.