Palmyra Township is one of ten townships in Knox County, Indiana. As of the 2020 census, its population was 1,512 (up from 1,466 at 2010) and it contained 632 housing units.
Shadowwood was added to the National Register of Historic Places in 2001. Rose Hill Farmstead was formerly listed.
According to the 2010 census, the township has a total area of , of which (or 99.97%) is land and (or 0.03%) is water.