19th century population The population of the village increased during the 19th century:
2011 census Castlederg is classified as an intermediate settlement by the
Northern Ireland Statistics and Research Agency (NISRA) (i.e. with a population between 2,500 and 4,999 people). On census day in 2011 (27 March 2011), the usually resident population of Castlederg Settlement was 2,976, accounting for 0.16% of the NI total. Of these: • 19.72% were under 16 years old and 16.97% were aged 65 and above. • 48.42% of the population were male and 51.58% were female. • 55.36% were from a Catholic community background and 40.22% were from a 'Protestant and Other Christian (including Christian related)' community background. • 36.56% indicated that they had a British national identity, 34.54% had an Irish national identity, and 30.51% had a Northern Irish national identity.
2021 census On census day in 2021 (21 March 2021), the usually resident population of Castlederg Settlement was 2,980. Of these: • 20.20% were aged under 16, 60.64% were aged between 16 and 65, and 19.16% were aged 66 and over. • 52.75% of the population were female and 47.25% were male. • 57.25% belong to or were brought up Catholic, 38.19% belong to or were brought up Protestant (including other Christian denominations), 0.94% belonged to or were brought up in an 'other' religion, and 3.62%
did not adhere to or had no religion. • 39.83% indicated they had an Irish national identity, 33.96% indicated they had a British national identity, 32.38% indicated they had a Northern Irish national identity, and 4.46% indicated they had an 'other' national identity. (respondents could indicate more than one national identity) • 13.36% had some knowledge of
Irish (Gaeilge) and 10% had some knowledge of
Ulster Scots. ==Climate==