Mark is a village in Putnam County, Illinois, United States. The population was 555 at the 2010 census, up from 491 in 2000. It is part of the Ottawa-Streator Micropolitan Statistical Area.Mark is located at 41°15′56″N 89°14′55″W / 41.265594°N 89.248521°W / 41.265594; -89.248521.According to the 2010 census, the village has a total area of 1.13 square miles, all land.As of the census of 2000, there were 491 people, 192 households, and 139 families residing in the village. The population density was 604.9 people per square mile. There were 209 housing units at an average density of 257.5 per square mile. The racial makeup of the village was 98.57% White and 1.43% Native American. Hispanic or Latino of any race were 4.68% of the population.There were 192 households out of which 35.4% had children under the age of 18 living with them, 58.3% were married couples living together, 10.9% had a female householder with no husband present, and 27.6% were non-families. 25.