Placentia (pləˈsɛnʃə) is a city in northern Orange County, California. Its population was 51,233 during the 2020 census, up from 46,488 in the 2000 census. This includes the community of Atwood, which is included in the city of Placentia, and is located in its southeastern quadrant. Primarily referred to as a bedroom community, Placentia is known for its quiet neighborhoods.
In 1971, Placentia was honored with the prestigious "All America City" award, given out annually by the National Civic League to 10 cities in the United States.
Indigenous peoples of California referred to by the Spanish as Gabrielenos, known as the Tongva, lived in the area for thousands of years. One estimate wrote that the native population in what was to become northern Orange County was at least 1,000. The large village of Hutuknga was closely situated to the area that is now Placentia.
In 1837, the Mexican government granted the area that is now Placentia to Juan Pacifi