| Muro Dam | |
| Location: | Campo Maior, Portalegre District, Portugal |
| Dam Length: | 174 m |
| Dam Height: | 4.6 m |
| Dam Width Base: | 4.2 m |
| Opening: | Roman period |
The Muro Dam was a Roman dam in Portugal. Located near the eastern municipality of Campo Maior, it is the largest surviving ancient dam in the country south of the Tagus river.
The 174 m long structure features three slight bends in its course. Its downstream side is supported by a series of thirteen small buttresses at intervals of 3–4 m. The central section, where the dam is highest and strongest, is further strengthened on its air-side by three vertical arches which go from buttress to buttress.