Lake Lillian has a total area of 0.46 square miles all of it land. Minnesota State Highway 7 serves as a main route in the community. Lake Lillian is a city in Kandiyohi County.
What is now Kandiyohi County there was two separate counties Kandiyohi and Monongalia. Both were established in 1858 and both functioned independently until the two counties merged twelve years later in an economical move. The people of the two counties realized that both counties were too small to function efficiently and economically as separate governmental units, so they formed one county government in a very lop-sided referendum.