Walnut Park first appeared as an unincorporated place in the
1970 United States census, and as a
census-designated place in the
1980 census as part of the Southeast census county division. The age distribution was 23.5% under the age of 18, 11.2% aged 18 to 24, 28.2% aged 25 to 44, 24.5% aged 45 to 64, and 12.5% aged 65 or older. The median age was 35.1 years. For every 100 females, there were 98.5 males, and for every 100 females age 18 and over there were 97.0 males age 18 and over. There were 3,726 households, of which 48.9% had children under the age of 18 living in them. Of all households, 49.8% were married-couple households, 8.0% were
cohabiting couple households, 15.9% were households with a male householder and no spouse or partner present, and 26.3% were households with a female householder and no spouse or partner present. About 9.7% of all households were made up of individuals and 3.6% had someone living alone who was 65 years of age or older. The average household size was 4.08, and there were 3,208
families (86.1% of all households).
2010 census At the
2010 census Walnut Park had a population of 15,966. The population density was . The racial makeup of Walnut Park was 9,046 (56.7%) White (1.7% Non-Hispanic White), 70 (0.4%) African American, 277 (1.7%) Native American, 89 (0.6%) Asian, 2 (0.0%) Pacific Islander, 5,953 (37.3%) from
other races, and 529 (3.3%) from two or more races. Hispanic or Latino of any race were 15,543 persons (97.4%). The census reported that 15,952 people (99.9% of the population) lived in households, 14 (0.1%) lived in non-institutionalized group quarters, and no one was institutionalized. There were 3,612 households, 2,128 (58.9%) had children under the age of 18 living in them, 2,060 (57.0%) were
opposite-sex married couples living together, 748 (20.7%) had a female householder with no husband present, 353 (9.8%) had a male householder with no wife present. There were 246 (6.8%)
unmarried opposite-sex partnerships, and 23 (0.6%)
same-sex married couples or partnerships. 317 households (8.8%) were one person and 130 (3.6%) had someone living alone who was 65 or older. The average household size was 4.42. There were 3,161 families (87.5% of households); the average family size was 4.51. The age distribution was 4,742 people (29.7%) under the age of 18, 1,849 people (11.6%) aged 18 to 24, 4,821 people (30.2%) aged 25 to 44, 3,266 people (20.5%) aged 45 to 64, and 1,288 people (8.1%) who were 65 or older. The median age was 30.2 years. For every 100 females, there were 101.5 males. For every 100 females age 18 and over, there were 101.3 males. There were 3,744 housing units at an average density of 5,007.0 per square mile, of the occupied units 1,924 (53.3%) were owner-occupied and 1,688 (46.7%) were rented. The homeowner vacancy rate was 1.1%; the rental vacancy rate was 3.6%. 9,340 people (58.5% of the population) lived in owner-occupied housing units and 6,612 people (41.4%) lived in rental housing units. ==Retail==