Santa Rosa, or Kaij Mek (O’odham), is a census-designated place (CDP) in Pima County, Arizona, United States. The population was 438 at the 2000 census.

Santa Rosa is located at32°19′33″N 112°2′34″W / 32.32583°N 112.04278°W / 32.32583; -112.04278 (32.325904, -112.042709).

According to the United States Census Bureau, the CDP has a total area of 5.7 square miles (15 km²), all of it land.

At the 2000 census there were 438 people, 132 households, and 97 families living in the CDP. The population density was 76.6 people per square mile (29.6/km²). There were 150 housing units at an average density of 26.2/sq mi (10.1/km²). The racial makeup of the CDP was 0.46% White, 99.09% Native American, 0.23% from other races, and 0.23% from two or more races. 0.91% of the population were Hispanic or Latino of any race.
Of the 132 households 32.6% had children under the age of 18 living with them, 28.0% were married couples living together, 28.8% had a female householder with no husband present, and 26.5% were non-families. 22.0% of households were one person and 9.1% were one person aged 65 or older. The average household size was 3.32 and the average family size was 3.86.

The age distribution was 33.6% under the age of 18, 8.7% from 18 to 24, 28.3% from 25 to 44, 18.9% from 45 to 64, and 10.5% 65 or older. The median age was 29 years. For every 100 females, there were 92.1 males. For every 100 females age 18 and over, there were 92.7 males.

The median household income was $9,688 and the median family income was $12,000. Males had a median income of $22,813 versus $23,438 for females. The per capita income for the CDP was $6,090. About 50.0% of families and 51.1% of the population were below the poverty line, including 54.5% of those under age 18 and 69.0% of those age 65 or over.