| Official Name: | O'Brien, Texas |
| Settlement Type: | City |
| Mapsize: | 250px |
| Image Map1: | Haskell County OBrien.svg |
| Mapsize1: | 250px |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Texas |
| Subdivision Type2: | County |
| Subdivision Name2: | Haskell |
| Unit Pref: | Imperial |
| Area Footnotes: | [1] |
| Area Total Km2: | 1.30 |
| Area Land Km2: | 1.30 |
| Area Water Km2: | 0.00 |
| Area Total Sq Mi: | 0.50 |
| Area Land Sq Mi: | 0.50 |
| Area Water Sq Mi: | 0.00 |
| Population As Of: | 2020 |
| Population Total: | 91 |
| Population Density Km2: | auto |
| Population Density Sq Mi: | auto |
| Timezone: | Central (CST) |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Elevation M: | 480 |
| Elevation Ft: | 1575 |
| Coordinates: | 33.38°N -99.8419°W |
| Postal Code Type: | ZIP code |
| Postal Code: | 79539 |
| Area Code: | 940 |
| Blank Name: | FIPS code |
| Blank Info: | 48-53304[2] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 1364256[3] |
O'Brien is a city in Haskell County, Texas, United States. The population was 91 at the 2020 census. O'Brien is located at the junction of Farm to Market Road 2229 and Texas State Highway 6; the nearest large city is Abilene, 70 miles to the south. The area was hit by a destructive and deadly F4 tornado on March 13, 1953.
According to the United States Census Bureau, the city has a total area of 0.5sqmi, all land.
As of the census of 2000, 132 people, 54 households, and 32 families resided in the city. The population density was 262.1sp=usNaNsp=us. The 71 housing units averaged 141.0/sq mi (54.8/km). The racial makeup of the city was 61.36% White, 0.76% Native American, 37.88% from other races. Hispanics or Latinos of any race were 55.30% of the population.
Of the 54 households, 24.1% had children under the age of 18 living with them, 46.3% were married couples living together, 9.3% had a female householder with no husband present, and 40.7% were not families. About 38.9% of all households were made up of individuals, and 24.1% had someone living alone who was 65 years of age or older. The average household size was 2.44 and the average family size was 3.34.
In the city, the population was distributed as 25.0% under the age of 18, 10.6% from 18 to 24, 15.9% from 25 to 44, 23.5% from 45 to 64, and 25.0% who were 65 years of age or older. The median age was 44 years. For every 100 females, there were 71.4 males. For every 100 females age 18 and over, there were 59.7 males.
The median income for a household in the city was $17,500, and for a family was $18,750. Males had a median income of $25,000 versus $13,214 for females. The per capita income for the city was $10,422. About 22.2% of families and 18.7% of the population were living below the poverty line, including 20.0% of those under 18 and 16.7% of those over 64.
The City of O'Brien is served by the Knox City-O'Brien Consolidated Independent School District.
In 1972, O'Brien won the first six-man football state championship in Texas.