| Official Name: | Na-Au-Say Township |
| Settlement Type: | Township |
| Image Map1: | Map of Illinois highlighting Kendall County.svg |
| Mapsize1: | 150px |
| Map Caption1: | Kendall County's location in Illinois |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Illinois |
| Subdivision Type2: | County |
| Subdivision Name2: | Kendall |
| Area Total Sq Mi: | 34.22 |
| Area Land Sq Mi: | 34.22 |
| Area Water Sq Mi: | 0 |
| Area Water Percent: | 0 |
| Population As Of: | 2010 |
| Population Density Sq Mi: | 238 |
| Elevation Footnotes: | [1] |
| Elevation M: | 186 |
| Elevation Ft: | 610 |
| Coordinates: | 41.5903°N -88.3125°W |
| Blank Name: | FIPS code |
| Blank Info: | 17-093-51531 |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 0429416 |
| Pop Est As Of: | 2016 |
| Pop Est Footnotes: | [2] |
| Population Est: | 8727 |
| Unit Pref: | Imperial |
Na-Au-Say Township occupies the 6 mile square on the eastern edge of Kendall County, Illinois. As of the 2010 census, its population was 8,145 and it contained 2,534 housing units.[3]
The township's name was chosen by popular vote and came from the Native American village on the Aux Sable Creek (a branch of which flows through the township), which was named for a Potawatomi leader.[4]
According to the 2010 census, the township has a total area of, all land.[3]
The population increased from 1,672 in 2000 to 8,145 due to developments, such as the Clublands, in the portions of Joliet and Plainfield that extend into the township.
The township is governed by an elected Town Board of a Supervisor and four Trustees. The Township also has an elected Assessor, Clerk, and Highway Commissioner and Supervisor.