2020 census As of the
2020 census, Brant Lake had a population of 56 and a median age of 61.3 years; 8.9% of residents were under the age of 18 and 35.7% were 65 years of age or older. For every 100 females there were 124.0 males, and for every 100 females age 18 and over there were 121.7 males age 18 and over. 0.0% of residents lived in urban areas, while 100.0% lived in rural areas. There were 23 households in Brant Lake, of which 34.8% had children under the age of 18 living in them. Of all households, 87.0% were married-couple households, 13.0% were households with a male householder and no spouse or partner present, and 0.0% were households with a female householder and no spouse or partner present. About 4.3% of all households were made up of individuals and 0.0% had someone living alone who was 65 years of age or older. There were 40 housing units, of which 42.5% were vacant. The homeowner vacancy rate was 0.0% and the rental vacancy rate was 0.0%. ==Education==