2020 census As of the
2020 census, Terryville had a population of 5,202. The median age was 42.7 years. 18.0% of residents were under the age of 18 and 18.0% of residents were 65 years of age or older. For every 100 females there were 102.8 males, and for every 100 females age 18 and over there were 101.2 males age 18 and over. 100.0% of residents lived in urban areas, while 0.0% lived in rural areas. There were 2,273 households in Terryville, of which 23.6% had children under the age of 18 living in them. Of all households, 41.8% were married-couple households, 23.1% were households with a male householder and no spouse or partner present, and 24.2% were households with a female householder and no spouse or partner present. About 31.7% of all households were made up of individuals and 13.4% had someone living alone who was 65 years of age or older. Of the 2,222 households, 30.6% had children under the age of 18 living with them, 48.0% were headed by
married couples living together, 10.7% had a female householder with no husband present, and 35.8% were non-families. Of all households, 28.2% were made up of individuals, and 11.3% were someone living alone who was 65 years of age or older. The average household size was 2.42 and the average family size was 2.97. ==Education==