| Old Brook | |
| Subdivision Type1: | Country |
| Subdivision Name1: | England |
| Source1 Location: | Crow Knowl |
| Mouth Location: | River Beal |
| Mouth Coordinates: | 53.5859°N -2.0887°W |
Old Brook is a small watercourse in Shaw and Crompton in the Metropolitan Borough of Oldham, Greater Manchester in the northwest of England. It flows from Crow Knowl on Crompton Moor to the River Beal. Its main feature is a waterfall at Pingot Quarry.