2020 census As of the
2020 census, Deer Park had a population of 1,294. The population density was . The age distribution was 190 people (14.7%) under the age of 18, 64 people (4.9%) aged 18 to 24, 239 people (18.5%) aged 25 to 44, 337 people (26.0%) aged 45 to 64, and 464 people (35.9%) who were 65 years of age or older. The median age was 56.0 years. For every 100 females, there were 79.2 males, and for every 100 females age 18 and over, there were 79.8 males age 18 and over. The census reported that 85.9% of the population lived in households, 0.4% lived in non-institutionalized group quarters, and 13.7% were institutionalized. There were 487 households, out of which 94 (19.3%) had children under the age of 18 living in them. Of these households, 218 (44.8%) were married-couple households, 31 (6.4%) were
cohabiting couple households, 142 (29.2%) had a female householder with no partner present, and 96 (19.7%) had a male householder with no partner present. 166 households (34.1%) were one person, and 75 (15.4%) were one person aged 65 or older. The average household size was 2.28. There were 290
families (59.5% of all households). There were 655 housing units at an average density of . Of those, 487 (74.4%) were occupied and 168 (25.6%) were vacant. Of occupied units, 281 (57.7%) were owner-occupied and 206 (42.3%) were occupied by renters. The homeowner vacancy rate was 1.7% and the rental vacancy rate was 5.9%. ==Government==