Hamilton is a city in and the county seat of Hamilton County, Texas, United States, located in the state's central region. Its population was 2,895 at the 2020 census.
Hamilton is located in central Hamilton County. U.S. Route 281 passes through the center of the city, leading north to Hico and south to Evant. Texas State Highway 36 (Main Street) crosses US 281 in the center of town and leads southeast to Gatesville and northwest to Comanche. Texas State Highway 22 leads northeast from Hamilton to Meridian.
According to the United States Census Bureau, the city has a total area of , of which , or 1.8%, is covered by water. The city is drained by Pecan Creek, an eastward-flowing tributary of the Leon River.
As of the 2020 census, Hamilton had a population of 2,895 people in 1,197 households, including 632 families. The median age was 42.6 years; 22.9% of residents were under the age of 18 and 24.6% were 65 years of age or older. For every 100 females there were 87.5 males, and for every 100 females age 18 and over there were 83.5 males age 18 and over.
0.0% of residents lived in urban areas, while 100.0% lived in rural areas.
There were 1,197 households in Hamilton, of which 28.3% had children under the age of 18 living in them. Of all households, 44.4% were married-couple households, 17.9% were households with a male householder and no spouse or partner present, and 31.7% were households with a female householder and no spouse or partner present. About 32.1% of all households were made up of individuals and 17.6% had someone living alone who was 65 years of age or older.
There were 1,395 housing units, of which 14.2% were vacant. The homeowner vacancy rate was 3.7% and the rental vacancy rate was 15.0%.
As of the census of 2010, 3,095 people, 1,230 households, and 777 families were residing in the city. The population density was 1,067.2 people/sq mi (412.7/km<sup>2</sup>). The 1,470 housing units averaged 506.9/sq mi (196 per km<sup>2</sup>). The racial makeup of the city was 94.5% White, 0.7% African American, 0.7% Native American, 0.5% Asian, 2.8% from other races, and 0.8% from two or more races. Hispanics or Latinos of any race were 8.9% of the population.
Of the 1,230 households, 26.9% had children under 18 living with them, 45.7% were married couples living together, 13.3% had a female householder with no husband present, 4.1% had a male householder with no wife present, and 36.8% were not families. About 32.1% of all households were made up of individuals, and 17.6% had someone living alone who was 65 years of age or older. The average household size was 2.38, and the average family size was 2.92.
In the city, the age distribution was 21.8% under 18, 27.9% from 18 to 44, 23.9% from 45 to 64, and 26.4% who were 65 or older. The median age was 45.2 years. For every 100 females, there were 86.4 males. For every 100 females age 18 and over, there were 82.2 males.
The median income for a household in the city was $26,585, and for a family was $38,702. Males had a median income of $27,074 versus $17,500 for females. The per capita income for the city was $15,012. About 12.2% of families and 15.9% of the population were below the poverty line, including 23.0% of those under age 18 and 16.1% of those age 65 or over.
The city is served by the Hamilton Independent School District.
The Hamilton County Courthouse, built in 1897, was added to the National Register of Historic Places in April 1980.
Hamilton is home to Hamilton Municipal Airport, a city-owned, public-use airport located at the south edge of the city.
The climate in this area is characterized by hot, humid summers and generally mild to cool winters. According to the Köppen climate classification, Hamilton has a humid subtropical climate, Cfa on climate maps.