| Official Name: | Spencer Township, Allen County, Ohio |
| Settlement Type: | Township |
| Mapsize: | 250px |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Ohio |
| Subdivision Type2: | County |
| Subdivision Name2: | Allen |
| Unit Pref: | Imperial |
| Area Total Km2: | 60.5 |
| Area Land Km2: | 60.4 |
| Area Water Km2: | 0.1 |
| Population As Of: | 2020 |
| Population Total: | 3067 |
| Population Density Km2: | 50.8 |
| Timezone: | Eastern (EST) |
| Utc Offset: | -5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | -4 |
| Elevation Footnotes: | [1] |
| Elevation M: | 251 |
| Elevation Ft: | 823 |
| Coordinates: | 40.7156°N -84.3583°W |
| Blank Name: | FIPS code |
| Blank Info: | 39-73982[2] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 1085700 |
Spencer Township is one of the twelve townships of Allen County, Ohio, United States. The 2020 census found 3,067 people in the township.[3]
Located in the southwestern corner of the county, it borders the following townships:
The village of Spencerville is located in southern Spencer Township.
Statewide, other Spencer Townships are located in Guernsey, Lucas, and Medina counties and formerly in Hamilton County.
The township is governed by a three-member board of trustees, who are elected in November of odd-numbered years to a four-year term beginning on the following January 1. Two are elected in the year after the presidential election and one is elected in the year before it. There is also an elected township fiscal officer,[4] who serves a four-year term beginning on April 1 of the year after the election, which is held in November of the year before the presidential election. Vacancies in the fiscal officership or on the board of trustees are filled by the remaining trustees.