Cowan is a census-designated place (CDP) in Stanislaus County, California. Cowan sits at an elevation of . The 2020 United States census reported Cowan's population was 342.
According to the United States Census Bureau, the CDP covers an area of 0.14 square miles (0.4 km<sup>2</sup>), all of it land.
The 2020 United States census reported that Cowan had a population of 342. The population density was . The racial makeup of Cowan was 139 (40.6%) White, 1 (0.3%) African American, 8 (2.3%) Native American, 4 (1.2%) Asian, 0 (0.0%) Pacific Islander, 143 (41.8%) from other races, and 47 (13.7%) from two or more races. Hispanic or Latino of any race were 227 persons (66.4%).
The whole population lived in households. There were 84 households, out of which 38 (45.2%) had children under the age of 18 living in them, 47 (56.0%) were married-couple households, 6 (7.1%) were cohabiting couple households, 11 (13.1%) had a female householder with no partner present, and 20 (23.8%) had a male householder with no partner present. 18 households (21.4%) were one person, and 8 (9.5%) were one person aged 65 or older. The average household size was 4.07. There were 66 families (78.6% of all households).
The age distribution was 108 people (31.6%) under the age of 18, 26 people (7.6%) aged 18 to 24, 94 people (27.5%) aged 25 to 44, 82 people (24.0%) aged 45 to 64, and 32 people (9.4%) who were 65years of age or older. The median age was 34.0years. For every 100 females, there were 97.7 males.
There were 97 housing units at an average density of , of which 84 (86.6%) were occupied. Of these, 50 (59.5%) were owner-occupied, and 34 (40.5%) were occupied by renters.