Rodeo is a census-designated place (CDP) located in Contra Costa County, California, in the East Bay sub-region of the San Francisco Bay Area, on the eastern shore of San Pablo Bay, 25 miles northeast of San Francisco. The population was 8,679 at the 2010 census. The town is named for the livestock roundups common in the late 19th century. Cattle from the surrounding hills were regularly driven down through the old town to a loading dock on the shoreline of San Pablo Bay for shipment to slaughterhouses, a practice which continued through the early 20th century. The town of Rodeo is served by the Interstate 80freeway and State Route 4. The Southern Pacific Railroad main line passes through Rodeo. Rodeo has not been a stop on the railroad since the 1950s.
The 2010 United States Census reported that Rodeo had a population of 8,679. The population density was 1,873.6 people per square mile (723.4/km²). The racial makeup of Rodeo was 3,823 (44.0%) White, 1,410 (16.2%) African American, 53 (0.6%) Native American, 1,762 (20.3%) Asian, 62 (0.7%) Pacific Islander, 885 (10.2%) from other races, and 684 (7.9%) from two or more races. Hispanic or Latino of any race were 2,134 people (24.6%).
The Census reported that 99.5% of the population lived in households and 0.5% lived in non-institutionalized group quarters.
There were 2,920 households, out of which 1,126 (38.6%) had children under the age of 18 living in them, 1,455 (49.8%) were opposite-sex married couples living together, 540 (18.5%) had a female householder with no husband present, 196 (6.7%) had a male householder with no wife present. There were 175 (6.0%) unmarried opposite-sex partnerships, and 21 (0.7%) same-sex married couples or partnerships. 583 households (20.0%) were made up of individuals and 207 (7.1%) had someone living alone who was 65 years of age or older. The average household size was 2.96. There were 2,191 families (75.0% of all households); the average family size was 3.40.
The population was spread out with 2,128 people (24.5%) under the age of 18, 802 people (9.2%) aged 18 to 24, 2,173 people (25.0%) aged 25 to 44, 2,517 people (29.0%) aged 45 to 64, and 1,059 people (12.2%) who were 65 years of age or older. The median age was 38.2 years. For every 100 females, there were 95.3 males. For every 100 females age 18 and over, there were 91.4 males.
There were 3,137 housing units at an average density of 677.2 per square mile (261.5/km²), of which 2,920 were occupied, of which 1,861 (63.7%) were owner-occupied, and 1,059 (36.3%) were occupied by renters. The homeowner vacancy rate was 2.3%; the rental vacancy rate was 7.4%. 5,508 people (63.5% of the population) lived in owner-occupied housing units and 3,130 people (36.1%) lived in rental housing units.