Deer Grove is a village in Whiteside County, Illinois, United States. The population was given as 45 in the 2010 census, down from 48 in 2000.Deer Grove is located at 41°36′28″N 89°41′30″W / 41.60778°N 89.69167°W / 41.60778; -89.69167.According to the 2010 census, Deer Grove has a total area of 0.46 square miles, all land.As of the census of 2000, there were 48 people, 21 households, and 12 families residing in the village. The population density was 105.3 people per square mile. There were 22 housing units at an average density of 48.3 per square mile. The racial makeup of the village was 91.67% White, 2.08% African American, 6.25% from other races. Hispanic or Latino of any race were 8.33% of the population.There were 21 households out of which 28.6% had children under the age of 18 living with them, 52.4% were married couples living together, 4.8% had a female householder with no husband present, and 38.1% were non-families. 33.