West Whittier-Los Nietos is a census-designated place (CDP) located in Los Angeles County, California, within the United States. It is situated near the San Gabriel River and the San Gabriel River (I-605) Freeway.
The census area for West Whittier-Los Nietos consists of two separate unincorporated communities: Los Nietos and West Whittier. According to the 2020 census, the total population was 25,325, reflecting a slight decrease from the 25,540 residents recorded in 2010.