Nicopolis ad Nestum (Ancient Greek: Νικόπολις ἡ περὶ Νέστον, Nikópolis hē perì Néston) or Nicopolis ad Mestum, is a ruined Roman town in the province of Thracia (Thrace) near to the modern village of Garmen on the left bank of the Mesta river, in Garmen Municipality, Bulgaria.

Several archaeological finds have been made, including a votive relief of the Thracian horseman, a statuette of Hermes, an old Christian tumulus, over 95 gold and 22 other coins, glass, bronze and ceramic vessels and a ritual table.

Battered coins of Nicopolis ad Istrum in Lower Moesia, perhaps the most prolific mint in the Roman Balkans in the early third century, are often mistaken for issues of Mestum.

[2] The emission of coins from Nicopolis ad Mestum has been dated to the year 211, more precisely to the period between the death of Septimius Severus in February and the murder of Geta in December, by the German scholar Holger Komnick, author of the only comprehensive study of the coinage of this city (in the series Griechisches Münzwerk of the Berlin-Brandenburg Academy of Sciences and Humanities).

The inscription is a letter from the Roman emperor Septimius Severus and his son Caracalla thanking the people of the city for a donation of 700,000 denarii.