Sozopol is located on the southern Bulgarian Black Sea coast, 35 kilometers south of Burgas. The town stretches between the foothills of the Strandzha Mountains to the south and the Bay of Burgas to the north. Sozopol is divided into an old town and a new town. The old town is situated on the small Skamnij Peninsula, which is 200 meters wide, nearly two kilometers long, and lies ten meters above sea level. To the west of this peninsula is Sozopol Bay, while to the east lies Korenjata Bay.

The eight-hectare island of Sveti Kirik was connected to the Skamnij Peninsula until the turn of the era. It is located 250 meters northwest of the old town and has been linked to the mainland by an artificial causeway since 1927, technically making it a peninsula. The causeway connects the northeast of the island to the old town. Since the Sveti Kirik Peninsula was extended southwestward by a 400-meter-long breakwater, an artificial bay measuring 800 × 200 meters was created to the west of the old town. The bay facing the mainland is home to the fishing and yacht harbor.

Since the early 1960s, Sozopol has expanded southward due to the growth of tourism. The new town of Sozopol and the most recent district, Charmanite, cover the coast of Korenjata Bay and the Budzhaka Peninsula. The latter is also popularly known as Germankata (“The German Woman”) after a German woman who had an accident there in 1959.

The old and new towns are connected by a land bridge, which was home to the city cemetery during the Middle Ages. This area has since been transformed into a park known as the Sea Garden. The Budzhaka Peninsula and Kavatsite Bay form the southern boundary of the city.

In Sozopol Bay, 1.2 kilometers north of the old town, lie the islands of Sveti Ivan and Sveti Petar. These two islands provide natural protection for the Sozopol anchorage against strong winds, a feature that was particularly valued by sailors in ancient times.