Castle Hill
census-designated place
Castle Hill Position in California.
Coordinates: 37°52′23″N 122°03′26″W / 37.87306°N 122.05722°W / 37.87306; -122.05722
Country	United States
State	California
County	Contra Costa
Area [1]
• Total	0.58 sq mi (1.51 km2)
• Land	0.58 sq mi (1.51 km2)
• Water	0.00 sq mi (0.00 km2)  0%
Elevation [2]	302 ft (92 m)
Population  (2020)
• Total	1,271
• Density	2,172.65/sq mi (839.56/km2)
Time zone	UTC-8 (Pacific (PST))
• Summer (DST)	UTC-7 (PDT)
FIPS code	06-11915
GNIS feature ID	2582967
U.S. Geological Survey Geographic Names Information System: Castle Hill, California

Castle Hill is a census-designated place^[3] in Contra Costa County, California. Castle Hill sits at an elevation of 302 feet (92 m). The 2010 United States census reported Castle Hill's population was 1,299.

The surrounding area was once inhabited by the Saklans. A Saklan village, which was possibly occupied from 1500 until 1772, is located near the mouth of Tice Creek. It contains multiple bedrock mortars used for processing acorns and other foodstuffs as well as a small spring. Its location along is not far from its confluence with the much larger Las Trampas Creek would have been advantageous to the Saklans who inhabited it. A small plaque marks the site which sits next to the bus stop at Tice Valley Boulevard and Montecillo Drive.^[4]

According to the United States Census Bureau, the CDP has a total area of 0.728 square miles (1.855 km²), all of it land.

Castle Hill first appeared as a census designated place in the 2010 U.S. Census formed from part of Alamo CDP.^[6]

At the 2010 census Castle Hill had a population of 1,299. The population density was 1,784.5 inhabitants per square mile (689.0/km²). The racial makeup of Castle Hill was 1,112 (85.6%) White, 29 (2.2%) African American, 1 (0.1%) Native American, 110 (8.5%) Asian, 2 (0.2%) Pacific Islander, 9 (0.7%) from other races, and 36 (2.8%) from two or more races. Hispanic or Latino of any race were 78 people (6.0%).^[7]

The census reported that 1,265 people (97.4% of the population) lived in households, 12 (0.9%) lived in non-institutionalized group quarters, and 22 (1.7%) were institutionalized.

There were 497 households, 147 (29.6%) had children under the age of 18 living in them, 322 (64.8%) were opposite-sex married couples living together, 32 (6.4%) had a female householder with no husband present, 15 (3.0%) had a male householder with no wife present. There were 19 (3.8%) unmarried opposite-sex partnerships, and 10 (2.0%) same-sex married couples or partnerships. 99 households (19.9%) were one person and 52 (10.5%) had someone living alone who was 65 or older. The average household size was 2.55. There were 369 families (74.2% of households); the average family size was 2.93.

The age distribution was 275 people (21.2%) under the age of 18, 62 people (4.8%) aged 18 to 24, 203 people (15.6%) aged 25 to 44, 472 people (36.3%) aged 45 to 64, and 287 people (22.1%) who were 65 or older. The median age was 50.3 years. For every 100 females, there were 97.7 males. For every 100 females age 18 and over, there were 93.9 males.

There were 523 housing units at an average density of 718.5 per square mile (277.4/km²),of which 497 were occupied, 441 (88.7%) by the owners and 56 (11.3%) by renters. The homeowner vacancy rate was 1.6%; the rental vacancy rate was 8.2%. 1,137 people (87.5% of the population) lived in owner-occupied housing units and 128 people (9.9%) lived in rental housing units.

Castle Hill is in the Walnut Creek Elementary School District and the Acalanes Union High School District.^[8]