| Do Saco River | |
| Source1 Location: | Rio de Janeiro state |
| Mouth: | Mangaratiba Bay |
| Subdivision Type1: | Country |
| Subdivision Name1: | Brazil |
The Do Saco River, also known as the Da Lapa River, is a river of Rio de Janeiro state in southeastern Brazil. It flows into Mangaratiba Bay, west of Rio de Janeiro city.