2020 census
As of the 2020 census, Lemoyne had a population of 4,659. The median age was 40.5 years. 19.1% of residents were under the age of 18 and 18.2% of residents were 65 years of age or older. For every 100 females there were 97.7 males, and for every 100 females age 18 and over there were 96.8 males age 18 and over.
100.0% of residents lived in urban areas, while 0.0% lived in rural areas.
There were 2,178 households in Lemoyne, of which 23.8% had children under the age of 18 living in them. Of all households, 35.8% were married-couple households, 24.4% were households with a male householder and no spouse or partner present, and 30.9% were households with a female householder and no spouse or partner present. About 40.1% of all households were made up of individuals and 14.3% had someone living alone who was 65 years of age or older. There were housing units at an average density of .
Age and gender
The median age was 38.3 years, with under the age of 5, in the 5 to 17 age range, in the 18 to 20 age range, in the 21 to 24 age range, in the 25 to 34 age range, in the 35 to 44 age range, in the 45 to 54 age range, in the 55 to 59 age range, in the 60 to 64 age range, in the 65 to 74 age range, in the 75 to 84 age range, and age 85 and over. were under the age 18 and were age 65 and over. of the population were females, giving a ratio of females to males. of those over the age of 18 were female with of those age 65 and over being female.