Nicopolis (meaning in Greek: city of victory) or Actia Nicopolis was an ancient city of Epirus, founded 31 BC by Octavian in memory of his victory over Antony and Cleopatra at Actium.

The colony, composed of settlers from a great many of the towns of the neighboring countries (Ambracia, Anactoriuni , Calydon, Argos Amphilochicum, Leucas etc), proved highly successful, and the city was considered the capital of southern Epirus and Acarnania, and obtained the right of sending five representatives to the Amphictyonic council.

On the spot where Octavian's own tent had been pitched he built a monument adorned with the beaks of the captured galleys; and in further celebration of his victory he instituted the so-called Actian games in honor of Apollo Actius.

The city was restored by the emperor Julian, and again after the Gothic invasion by Justinian; but in the course of the Middle Ages it was supplanted by the town of Preveza. The ruins of Nicopolis, now known as Palaia Preveza (Old Preveza) lie about 3 miles North of that city, on a small bay of the Gulf of Arta (Sinus Ambracius) at the narrowest part of the isthmus of the peninsula which separates the gulf from the Ionian Sea. Besides the Acropolis, the most conspicuous objects are two theatres (the larger with 77 rows of seats) and an aqueduct which brought water to the town from a distance of 27 miles.

There are several other places named Nicopolis:

• a city in Asia Minor, founded by Leo III in 740, on the spot where he defeated an Arab army (see: Afyonkarahisar)
• a city in Cappadocia in the valley of the Lycus, founded by Pompey on the spot where he defeated Mithradates
• a city in Egypt, founded by Octavian 24 BC to commemorate his final victory over Antony
• a city in Thrace at the junction of the latrus with the Danube, founded by Trajan in memory of his victory over the Dacians (see: Nicopolis, Bulgaria)