Ahtopol (Bulgarian: Ахтопол, Greek: Αγαθόπολις, Agathopolis) is a town and seaside resort on the southern Bulgarian Black Sea Coast. It is located on a headland in the southeastern part of Burgas Province and is close to the border with European Turkey. It is the southernmost town on the Bulgarian coast.

The town lies on the site of an ancient Thracian settlement, with the earliest traces of human settlement dating to the Neolithic. It was probably colonized by the Ancient Greeks around 430 BC. The Romans called it Peronticus, while the Byzantine leader Agathon reconstructed the town after barbarian invasions and possibly gave it his own name, Agathopolis. According to other sources, it was named thus as early as 323 BC.

In the Middle Ages, the town frequently changed hands between the Byzantine Empire and the Bulgarian Empire. Medieval sources mention Ahtopol as a lively merchant port where many Byzantine, Italian and other ships arrived. With the invasion of the Ottoman troops at the end of the 14th century, the town was called Ahtenbolu. The town ultimately fell under Ottoman rule as late as 1453. An Ottoman tax register of 1498 lists 158 Christian families in Ahtopol, most of which have Greek names but others evidently Slavic (Bulgarian). In 1898, Ahtopol was a town of 410 houses, of which 300 Greek and 110 Bulgarian. In the 19th century, it was still a thriving centre of fishery and overseas trade, with many locals owning their own ships and selling goods all around the Black Sea and the Mediterranean. Viticulture was also well-developed.