| Official Name: | Andover Township |
| Settlement Type: | Township |
| Image Map1: | Map of Illinois highlighting Henry County.svg |
| Mapsize1: | 150px |
| Map Caption1: | Henry County's location in Illinois |
| Subdivision Type: | Country |
| Subdivision Type1: | State |
| Subdivision Type2: | County |
| Subdivision Name2: | Henry |
| Established Title: | Established |
| Established Date: | November 4, 1856 |
| Unit Pref: | Imperial |
| Area Total Sq Mi: | 36.58 |
| Area Land Sq Mi: | 36.58 |
| Area Water Sq Mi: | 0 |
| Area Water Percent: | 0 |
| Population As Of: | 2010 |
| Population Density Sq Mi: | 26.1 |
| Elevation M: | 244 |
| Elevation Ft: | 801 |
| Coordinates: | 41.2875°N -90.2617°W |
| Timezone: | CST |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Postal Code Type: | ZIP codes |
| Postal Code: | 61233, 61238, 61262, 61274 |
| Blank Name: | FIPS code |
| Blank Info: | 17-073-01504 |
| Pop Est As Of: | 2016 |
| Pop Est Footnotes: | [1] |
| Population Est: | 881 |
Andover Township is one of twenty-four townships in Henry County, Illinois, USA. As of the 2020 census, its population was 881 and it contained 399 housing units.[2]
According to the 2010 census, the township has a total area of, all land.[2]
The township contains these three cemeteries: Andover Township, Presbyterian and Rose Dale.