The most common responses for religious affiliation for persons usually resident in Castle Hill were Catholic 32.8%, Anglican 21.9%, No Religion 11.6%, Uniting Church 4.8% and Presbyterian and Reformed 3.1%.

There were 9,618 families in Castle Hill: 58.0% were couple families with children, 30.8% were couple families without children, 10.3% were one parent families and 0.9% were other families.

English was stated as the only language spoken at home by 74.0% of persons usually resident in Castle Hill. The most common languages other than English spoken at home were: Cantonese 3.9%, Mandarin 2.0%, Arabic 1.5%, Italian 1.4% and Korean 1.3%.

* statistcs taken from the 2006 Census for postal area 2154 conducted by the Australian Bureau of Statistics