The first people living in the area now known as Cypress were the Gabrieleno, a Native American tribe of the Tongva people. They were displaced soon after the arrival of the Europeans. The government of Spain then possessed the land until Mexico gained its independence in 1821. Mexico then lost Alta California to the United States during the period following the Bear Flag Rebellion and then the Mexican-American War.
The original Spanish dons held immense tracts of land throughout California, which were given in lieu of pay to Spanish soldiers. Manuel Nieto was one of the early Spanish dons or landowners in the area. After his death in 1804, his sons retained title to his holdings, but these lands were eventually broken up and distributed among them in 1833 by a grant from the Mexican governor José Figueroa. Manuel's son, Juan José Nieto, retained the title to a large portion of his father's original properties in southern California that included the present-day area of Cypress. That land and other Rancho properties were finally sold to the American Abel Stearns, then acquired by the Robinson Trust, a group of investors, which eventually parlayed their holdings into a vast land speculation business.
Cypress was originally nicknamed "Waterville" due to the preponderance of artesian wells in the area, but was incorporated under the name Dairy City in 1956 by local dairy farmers as a way to stave off developers and to preserve their dairies, much like the then-neighboring cities of Dairy Valley in Cerritos and Dairyland in La Palma. However, after World War II the land became too valuable for farming or ranching, and one-by-one, the dairies sold out to housing developers during the 1960s. By the 1970s, no dairies remained. (Many of the dairymen moved their operations to Chino, California, where development is once again pushing them out of the area.
In 1957, local residents voted to change the name of Dairy City to "Cypress". The name was taken from Cypress Elementary School, originally built in 1895, which took its name from the Cypress trees planted to protect the schoolhouse from the seasonal Santa Ana winds. Cypress Elementary School also provided the name for new Pacific Electric Railroad station on Walker Street at Lincoln Avenue when the Santa Ana Line was completed in 1906, as "Waterville" had already been used elsewhere in the system.
Cypress is approximately north of Bolsa Chica. The closest beach to Cypress is Seal Beach, which is roughly away from the center of Cypress. Cypress is less than a 20 minute drive from Long Beach Airport.
There were 15,654 households out of which 38.8% had children under the age of 18 living with them, 60.0% were married couples living together, 13.3% had a female householder with no husband present, and 21.8% were non-families. 17.6% of all households were made up of individuals and 6.6% had someone living alone who was 65 years of age or older. The average household size was 2.93 and the average family size was 3.31.
In the city the population was spread out with 27.0% under the age of 18, 7.9% from 18 to 24, 30.2% from 25 to 44, 24.4% from 45 to 64, and 10.6% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 94.9 males. For every 100 females age 18 and over, there were 90.5 males.
The median income for a household in the city was $64,377, and the median income for a family was $70,060. Males had a median income of $50,781 versus $36,337 for females. The per capita income for the city was $25,798. About 4.6% of families and 6.0% of the population were below the poverty line, including 7.2% of those under age 18 and 5.1% of those age 65 or over.
The 2008 population estimated by the California Department of Finance was 49,541.