Sillen

{{Infobox body of water

|name = Sillen

|image = Sillen.JPG

|image_size = 250

|alt = View of lake

|pushpin_map = Sweden Södermanland

|pushpin_map_alt = Location of lake

|image_bathymetry =

|caption_bathymetry =

|coords = {{coord|58|59|N|17|22|E|display=title,inline|region:SE_type:waterbody_source:GNS-enwiki}}

|type =

|inflow =

|outflow =

|catchment =

|basin_countries = Sweden

|length =

|width =

|area =

|depth =

|max-depth =

|volume =

|residence_time =

|shore =

|elevation =

|cities =

|reference =

}}

Sillen is a lake in Södermanland, Sweden. It straddles the boundary between Gnesta Municipality in Södermanland County and Södertälje Municipality in Stockholm County.