There were 537 households out of which 38.2% had children under the age of 18 living with them, 56.1% were married couples living together, 11.5% had a female householder with no husband present, and 27.0% were non-families. 19.6% of all households were made up of individuals and 4.3% had someone living alone who was 65 years of age or older. The average household size was 2.71 and the average family size was 3.12.
In the town the population was spread out with 26.3% under the age of 18, 6.7% from 18 to 24, 32.1% from 25 to 44, 24.8% from 45 to 64, and 10.2% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 101.4 males. For every 100 females age 18 and over, there were 99.3 males.
The median income for a household in the town was $50,652, and the median income for a family was $53,167. Males had a median income of $31,100 versus $28,375 for females. The per capita income for the town was $24,503. About 6.3% of families and 8.3% of the population were below the poverty line, including 8.9% of those under age 18 and 7.0% of those age 65 or over.
As of 2000, Haverhill had the fifty-eighth highest percentage of Cuban residents in the US, with 6.63% of the populace. It also had the forty-second highest percentage of Jamaican residents in the US, at 3.10% of the town's population.