There were 1,434 households out of which 58.5% had children under the age of 18 living with them, 65.2% were married couples living together, 17.0% had a female householder with no husband present, and 10.7% were non-families. 7.9% of all households were made up of individuals and 4.0% had someone living alone who was 65 years of age or older. The average household size was 4.69 and the average family size was 4.78.
In the CDP the population was spread out with 37.1% under the age of 18, 13.2% from 18 to 24, 30.4% from 25 to 44, 13.7% from 45 to 64, and 5.6% who were 65 years of age or older. The median age was 25 years. For every 100 females there were 106.8 males. For every 100 females age 18 and over, there were 109.9 males.
The median income for a household in the CDP was $38,594, and the median income for a family was $38,021. Males had a median income of $25,781 versus $23,409 for females. The per capita income for the CDP was $10,729. About 14.6% of families and 19.2% of the population were below the poverty line, including 23.0% of those under age 18 and 5.4% of those age 65 or over.
As an unincorporated area, the Monterey County Board of Supervisors administers Castroville. Castroville is part of District 2 whose current supervisor is Louis R. Calcagno The Board is responsible for providing all local public services
California Highways 1, 156, and 183 intersect in Castroville. Highway 156 connects to the 101. Highway 1 provides access from Monterey and Santa Cruz. Highway 183 connects Castroville to Salinas. Merritt Street serves as Castroville main drag. Most of Castroville's commerce and the post office are located on Merrit Street. Other major roads include Castroville Blvd., Blackie Road, and Preston Street.