Boulder Hill is a census-designated place (CDP) in Oswego Township, Kendall County, Illinois, United States.

Up until the early 2000s, the Boulder Hill subdivision had a small development area, equating to almost a town square.

The community itself has a strong identity, as the people from Boulder Hill are not classified as being from Montgomery or Oswego, two nearby larger towns.

Governmental services provided to Boulder Hill primarily come from either Kendall County or Oswego Township offices.

The villages of Oswego and Montgomery have both expanded their communities up to the boundaries of Boulder Hill, so there is no room for further business expansion.

So while Boulder Hill was previously known for having low property taxes because it does not have its own government, that is no longer the case. '