| Marsh Run | |
| Name Other: | Tributary to Oil Creek |
| Map Size: | 300 |
| Map Alt: | Map of the mouth of Marsh Run |
| Pushpin Map: | Pennsylvania#USA |
| Pushpin Map Size: | 300 |
| Pushpin Map Alt: | Location of the mouth of Marsh Run |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | Pennsylvania |
| Subdivision Type3: | County |
| Subdivision Name3: | Crawford |
| Subdivision Type4: | City |
| Subdivision Name4: | Hydetown |
| Length: | 4miles |
| Discharge1 Location: | Hydetown, Pennsylvania |
| Discharge1 Avg: | 16.43cuft/s[1] |
| Source1: | divide between Marsh Run and Muddy Creek |
| Source1 Location: | near McGinnet Corners, Pennsylvania |
| Source1 Coordinates: | 41.725°N -79.8033°W[2] |
| Source1 Elevation: | 1600feet[3] |
| Mouth: | about 0.5 miles south of Tryonville, Pennsylvania |
| Mouth Location: | Tryonville, Pennsylvania |
| Mouth Coordinates: | 41.6847°N -79.7831°W[4] |
| Mouth Elevation: | 1250feet[5] |
| Progression: | Oil Creek → Allegheny River → Ohio River → Mississippi River → Gulf of Mexico |
| River System: | Allegheny River (Oil Creek) |
| Tributaries Right: | DeWolfe Run |
| Bridges: | Armstrong Road Old Grade Road Tryonville Road |
Marsh Run is a 4.0-mile (6.4 km)[6] long tributary to Oil Creek in Crawford County, Pennsylvania.