According to the United States Census Bureau, Brazoria has a total area of 2.6 square miles (6.8 km2), all land.

[4] As of the 2020 United States census, there were 2,866 people, 1,171 households, and 869 families residing in the city.

The community's 1884 population was served by 12 general stores, five churches, three hotels, good schools, cotton gins, and sugar mills.

Two years later the Velasco World weekly newspaper began publishing in the town.

The local discovery of oil and sulphur in 1939 and the construction of a bridge across the Brazos River helped restore the town's fortunes.

Brazoria celebrates Frontier Days in March, the No Name Festival in June, and the Santa Ana Ball in July.

[9] The Texas Department of Criminal Justice operates the Clemens Unit in an unincorporated area near Brazoria.

Brazoria is served by West Brazos EMS which is operated by Sweeny Community Hospital.

Eagle Air Park (IATA code BZT) is the city airport.

The climate in this area is characterized by hot, humid summers and generally mild to cool winters.