Demographics
The population was 25,325 at the 2020 census, down from 25,540 at the 2010 census. The census area consists of separate unincorporated communities of Los Nietos and West Whittier.
As of the 2020 census, West Whittier-Los Nietos had a population of 25,325 and a population density of 10,049.6 inhabitants per square mile (3,880.2/km2). The median age was 37.9 years; 21.8% were under 18, 9.9% were aged 18 to 24, 27.7% were aged 25 to 44, 25.2% were aged 45 to 64, and 15.3% were 65 years of age or older. For every 100 females, there were 94.6 males, and for every 100 females age 18 and over there were 92.7 males age 18 and over.[25][26]