| Unit Pref: | Imperial |
| Settlement Type: | Township |
| Official Name: | Lancaster Township |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Illinois |
| Subdivision Type2: | County |
| Subdivision Name2: | Stephenson |
| Leader Title: | Supervisor |
| Leader Name: | Lowell Dickman |
| Area Total Sq Mi: | 32.08 |
| Area Land Sq Mi: | 32.01 |
| Area Water Sq Mi: | 0.07 |
| Area Water Percent: | 0.22 |
| Population As Of: | 2010 |
| Population Density Sq Mi: | 49.6 |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Coordinates: | 42.3331°N -89.5678°W |
| Elevation Ft: | 860 |
| Pop Est As Of: | 2016 |
| Pop Est Footnotes: | [1] |
| Population Est: | 1529 |
| Blank Name: | FIPS code |
| Blank Info: | 17-177-41885 |
Lancaster Township is located in Stephenson County, Illinois. As of the 2010 census, its population was 1,587 and it contained 692 housing units.[2]
Lancaster is Township 27 North, Range 8 East of the Fourth Principal Meridian.
According to the 2010 census, the township has a total area of, of which (or 99.78%) is land and (or 0.22%) is water.[2]