Lake Township is one of seventeen townships in Kosciusko County, Indiana, United States. As of the 2020 census, its population was 1,549 (down from 1,588 at 2010) and it contained 743 housing units.
Lake Township was organized in 1870.
According to the 2010 census, the township has a total area of , of which (or 98.11%) is land and (or 1.89%) is water.