Of Southbury's 7,225 households, 29.0% had children under the age of 18 living with them, 59.8% were married couples living together, 5.4% had a female householder with no husband present, and 33.1% were non-families.
The median income for a household in Southbury is $75,970 in 2007, compared to $61,919 in 1999; the median income for a family in 1999 was $81,109.