As of the census of 2000, there were 2,414 people, 869 households, and 641 families residing in the town. The population density was . There were 1,646 housing units at an average density of . The racial makeup of the town was 97.14% White, 1.70% Black or African American, 0.25% Native American, 0.25% Asian, 0.12% from other races, and 0.54% from two or more races. Hispanic or Latino of any race were 0.58% of the population.

There were 869 households, out of which 38.1% had children under the age of 18 living with them, 57.8% were married couples living together, 9.0% had a female householder with no husband present, and 26.2% were non-families. 18.9% of all households were made up of individuals, and 6.0% had someone living alone who was 65 years of age or older. The average household size was 2.78 and the average family size was 3.13. The Presbyterian Church in Theresa has a plaque and dedication for the Flower family.

Nicholas Doxtater Yost, related by marriage to Governor Flower, traveled from Johnstown, New York, to the Parker Settlement, now called Theresa in 1837, purchased land and settled down. Nicholas' son George, who become a prominent citizen, built a house that survived the great fires of Theresa. The most prominent Yost descendant was United Nations Ambassador Charles W. Yost.

Born in Theresa, Roscoe Drummond (1902–1983) was a political journalist known for his long association with The Christian Science Monitor and a widely syndicated column, "State of the Nation", that he wrote for more than 50 years,

Communities and locations in Theresa

  • Bartletts Corners – A hamlet by the southeastern town line, south of Red Lake.
  • Butterfield Lake – A lake at the northwestern town line, partly in the town.
  • Chapel Corners – A location on County Road 21, by Lake of the Woods.
  • Coopers Corners – A hamlet on combined routes NY-26 and NY-37, and County Road 193, west of Theresa village.
  • Crystal Lake – A lake near NY-26 by the northwestern town line.
  • Douglas Crossing – A hamlet on NY-37, located south of Theresa village.
  • Grass Lake – A lake partly in the town and partly in St. Lawrence County.
  • Hyde Lake – A lake on the western side of Theresa.
  • Indian River – A stream flowing through the town.
  • Indian River Wildlife Management Area – A conservation area in the town.
  • Lake of the Woods – A lake in the northern part of town, south of Grass Lake.
  • Millsite Lake – A lake by the northwestern town line, south of Butterfield Lake.
  • Moon Lake – A lake south of Bartletts Corners and Red Lake.
  • Muskellunge Lake – A lake near the northeastern corner of Theresa, east of Bartletts Corners.
  • Red Lake – A lake by Bartletts Corners and the northeastern town line.
  • Rivergate – A hamlet on County Road 46 and the Indian River, south of Theresa village.
  • Shurtleff Corners – A location on the southeastern town line on NY-26.
  • Sixberry Lake – A lake south of Millsite Lake.
  • Stills Corner – A location by the western corner of Theresa.
  • Stroughs Crossing – A location on NY-411 in the western part of the town.
  • Theresa – A village on the Indian River and NY-26.

References

  • Town of Theresa official website