| Official Name: | Allen Township |
| Settlement Type: | Township |
| Image Map1: | Map of Illinois highlighting LaSalle County.svg |
| Mapsize1: | 150px |
| Map Caption1: | LaSalle County's location in Illinois |
| Subdivision Type: | Country |
| Subdivision Type1: | State |
| Subdivision Type2: | County |
| Subdivision Name2: | LaSalle |
| Established Title: | Established |
| Established Date: | November 6, 1849 |
| Unit Pref: | Imperial |
| Area Total Sq Mi: | 36.23 |
| Area Land Sq Mi: | 36.23 |
| Area Water Sq Mi: | 0 |
| Area Water Percent: | 0 |
| Population As Of: | 2010 |
| Population Density Sq Mi: | 16.1 |
| Elevation M: | 211 |
| Elevation Ft: | 692 |
| Coordinates: | 41.1544°N -88.645°W |
| Timezone: | CST |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Postal Code Type: | ZIP codes |
| Postal Code: | 60437, 60470, 61364 |
| Blank Name: | FIPS code |
| Blank Info: | 17-099-00763 |
| Pop Est As Of: | 2016 |
| Pop Est Footnotes: | [1] |
| Population Est: | 564 |
Allen Township is one of thirty-seven townships in LaSalle County, Illinois, USA. As of the 2010 census, its population was 584 and it contained 259 housing units.[2] Allen Township was formed from Bruce Township on an unknown date. The township bears the name of Allen Stevens, a pioneer settler.[3]
According to the 2010 census, the township has a total area of, all land.[2]
The township contains these two cemeteries: Allen and Saint Patrick's Catholic.