According to the 2010 United States Census, the population of Santa Rosa was 167,815 residents. The population was split into 63,590 households and 39,231 families. At the time, there was a population density of 4,043.8 people per square mile.
Of the households, 44% had opposite-sex married couples, 7.9% had unmarried opposite-sex partnerships, and 1.2% had same-sex married couples or partnerships. 32.4% of households had children under the age of 18 years old, 28.3% had individuals residing alone, and 11.8% had an individual 65 years of age or older living alone. 12.1% of the household population had a single female head-of-house and 5.7% had a single male head-of-house. The average household size was 2.6 and the average family size was 3.2.
The age range of Santa Rosa in 2010 was broken up as follows: 23.4% of people were under the age of 18, 9.5% of people were between 18 and 24, 27.8% of people were between 25 and 44, 25.8% of people were between 45 and 64, and 13.5% of people were 65 years of age or older. The median age was 36.7 years old.
The racial makeup of Santa Rosa was as follows: 71% white residents, 28.6% Hispanic or Latino residents, 5.2% Asian residents, 2.4% black residents, 1.7% Native American residents, and .5% Pacific Islander residents. 14.1% of Santa Rosa residents identified as an “other” race and 5.1% identified as two or more races.