Cass Township is one of twenty-one townships in LaPorte County, Indiana. As of the 2020 census, its population was 1,825 (a tiny decrease of 1,833 from 2010) and it contained 764 housing units.
Cass Township was established in 1848. It was named for Lewis Cass, Democratic candidate in the 1848 United States presidential election.
According to the 2010 census, the township has a total area of , all land.