Hacienda Heights is an unincorporated community located in the San Gabriel Valley of Los Angeles County, California, in the United States. For statistical purposes, it is defined as a census-designated place (CDP).
The community is notable for its size within the region; it ranks as the third largest CDP in Los Angeles County by area, trailing only Topanga and Rowland Heights. By population, it is the fourth largest CDP in the county, with a recorded population of 54,191 as of the 2020 census.