Messad (sometimes Messaad; Arabic: مسعد) is a town in Algeria.

[2] It is unclear if the second part of the name, Dimmidi, was a native name transliterated into Latin, or a new name given by the Romans.

As the Castellum (castle) implies, the settlement was a fortress along the Limes Tripolitanus, the southern border of the province of Numidia.

It was a prosperous village and hosted a Roman garrison from roughly 198 to 240 AD.

This article about a location in Djelfa Province is a stub.