| Official Name: | Greencastle Township |
| Settlement Type: | Township |
| Mapsize: | 290px |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Indiana |
| Subdivision Type2: | County |
| Subdivision Name2: | Putnam |
| Government Type: | Indiana township |
| Area Total Sq Mi: | 34.44 |
| Area Land Sq Mi: | 34.32 |
| Area Water Sq Mi: | 0.12 |
| Population As Of: | 2020 |
| Population Total: | 12554 |
| Population Density Sq Mi: | auto |
| Timezone: | Eastern (EST) |
| Utc Offset: | -5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | -4 |
| Elevation Footnotes: | [1] |
| Elevation M: | 253 |
| Elevation Ft: | 830 |
| Coordinates: | 39.6436°N -86.8469°W |
| Area Code: | 765 |
| Blank Name: | FIPS code |
| Blank Info: | 18-29376[2] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 453347 |
Greencastle Township is one of thirteen townships in Putnam County, Indiana. As of the 2020 census, its population was 12,554 (down from 13,136 at 2010[3]) and it contained 5,002 housing units.[4] This township contains the county seat of Greencastle and is home to DePauw University, a liberal arts college of 2,300 students.
Forest Hill Cemetery and the Alfred Hirt House are listed on the National Register of Historic Places.[5]
According to the 2010 census, the township has a total area of, of which (or 99.65%) is land and (or 0.35%) is water.[3]
(This list is based on USGS data and may include former settlements.)
It is in Greencastle Community School Corporation,[6] which includes Greencastle High School.