| Muddy Creek | |
| Name Other: | Tributary to Slippery Rock Creek |
| Map Size: | 300 |
| Pushpin Map: | USA Pennsylvania#USA |
| Pushpin Map Size: | 300 |
| Pushpin Map Caption: | Location of Muddy Creek mouth |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | Pennsylvania |
| Subdivision Type3: | Counties |
| Subdivision Name3: | Butler Lawrence |
| Length: | 20.14miles[1] |
| Discharge1 Location: | Slippery Rock Creek |
| Discharge1 Avg: | 80.66cuft/s at mouth with Slippery Rock Creek[2] |
| Source1: | divide between Muddy Creek and Allegheny River |
| Source1 Location: | about 1 mile southeast of West Sunbury, Pennsylvania[3] |
| Source1 Coordinates: | 40.9942°N -80.1794°W[4] |
| Source1 Elevation: | 1370feet |
| Mouth: | Slippery Rock Creek |
| Mouth Location: | about 0.5 miles downstream of Kennedy Mill |
| Mouth Coordinates: | 40.98°N -79.8753°W |
| Mouth Elevation: | 1040feet |
| Progression: | Slippery Rock Creek → Connoquenessing Creek → Beaver River → Ohio River → Mississippi River → Gulf of Mexico |
| River System: | Beaver River |
| Tributaries Left: | Swamp Run Shannon Run Big Run Bear Run |
| Tributaries Right: | unnamed tributaries |
| Waterbodies: | Lake Arthur |
| Bridges: | Vidic Road, W Sunbury Road, N Beaver Dam Road, Shroyer Mill Road, William Flynn Highway (PA 8), PA 528, W Park Road, I-79, Currie Road, Book Road, US 19 |
Muddy Creek is a tributary of Slippery Rock Creek in Butler and Lawrence Counties in Pennsylvania in the United States. The run is 23.2miles long, flows generally west, and its watershed is 58.2sqmi in area.[5] Muddy Creek is the main water source for Lake Arthur in Moraine State Park.