2020 census As of the
2020 census, there were 4,936 people, 1,743 households, and 1,533 families residing in the city. The median age was 41.1 years; 25.3% of residents were under the age of 18 and 18.4% of residents were 65 years of age or older. For every 100 females there were 98.6 males, and for every 100 females age 18 and over there were 94.6 males age 18 and over. 96.9% of residents lived in urban areas, while 3.1% lived in rural areas. Of the 1,743 households in Willow Park, 39.7% had children under the age of 18 living in them. Of all households, 70.1% were married-couple households, 11.3% were households with a male householder and no spouse or partner present, and 16.1% were households with a female householder and no spouse or partner present. About 15.2% of all households were made up of individuals and 7.6% had someone living alone who was 65 years of age or older. There were 1,819 housing units, of which 4.2% were vacant. The homeowner vacancy rate was 2.4% and the rental vacancy rate was 7.7%. ==Education==