| Official Name: | South Muddy Township |
| Settlement Type: | Township |
| Image Map1: | Map of Illinois highlighting Jasper County.svg |
| Mapsize1: | 150px |
| Map Caption1: | Jasper County's location in Illinois |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Illinois |
| Subdivision Type2: | County |
| Subdivision Name2: | Jasper |
| Established Title: | Established |
| Established Date: | November 8, 1859 |
| Area Total Sq Mi: | 38.61 |
| Area Land Sq Mi: | 35.69 |
| Area Water Sq Mi: | 2.93 |
| Area Water Percent: | 7.59 |
| Population As Of: | 2010 |
| Population Density Sq Mi: | 9.5 |
| Elevation M: | 159 |
| Elevation Ft: | 522 |
| Coordinates: | 38.9011°N -88.3139°W |
| Timezone: | CST |
| Utc Offset: | -6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | -5 |
| Postal Code Type: | ZIP codes |
| Postal Code: | 62424, 62434, 62448, 62479 |
| Blank Name: | FIPS code |
| Blank Info: | 17-079-71084 |
| Pop Est As Of: | 2016 |
| Pop Est Footnotes: | [1] |
| Population Est: | 336 |
| Unit Pref: | Imperial |
South Muddy Township is one of eleven townships in Jasper County, Illinois, USA. As of the 2010 census, its population was 340 and it contained 137 housing units.[2]
According to the 2010 census, the township has a total area of, of which (or 92.44%) is land and (or 7.59%) is water.[2]
The township contains these ten cemeteries: Abbott, Devore, Foster, Freeman, Fulks, Headyville, Pleasant Valley, South Muddy, Worthey and Worthy.