2020 census As of the
2020 census, Cortland had a population of 4,398. The median age was 33.0 years. 28.8% of residents were under the age of 18 and 7.2% of residents were 65 years of age or older. For every 100 females there were 98.0 males, and for every 100 females age 18 and over there were 95.9 males age 18 and over. 94.1% of residents lived in urban areas, while 5.9% lived in rural areas. There were 1,521 households in Cortland, of which 45.9% had children under the age of 18 living in them. Of all households, 54.9% were married-couple households, 14.9% were households with a male householder and no spouse or partner present, and 21.2% were households with a female householder and no spouse or partner present. About 17.3% of all households were made up of individuals and 5.8% had someone living alone who was 65 years of age or older.
Income and poverty The median income for a household in the town was $74,821, and the median income for a family was $98,984. Males had a median income of $51,393 versus $26,688 for females. The
per capita income for the town was $32,578. About 0.6% of families and 4.5% of the population were below the
poverty line, including 0.5% of those under age 18 and 3.3% of those age 65 or over. ==Notable person==