Zarzis also known as Jarjis (Arabic: جرجيس gergīs / zerzīsⓘ) is a coastal commune (municipality) in southeastern Tunisia, former bishopric and Latin Catholic titular see under its ancient name Gergis.

The city was known in Antiquity as Gergis and located at the western end of the Lesser Syrtis (Gulf of Gabès), not far from the island of Meninx (current Djerba).

The town may owe its name and/or origin to the Biblical tribes of Girgashites which, according to ancient Jewish writers, had left the Canaan at the time of Joshua and went to settle in North Africa.

Gergis was important enough in the Roman province of Tripolitania (in the papal sway) to become a suffragan bishopric, which was to fade, presumably at the seventh century advent of Islam.

It has had the following incumbents, so far of the fitting Episcopal (lowest) rank : Economic activity of Zarzis is mainly based on tourism, fishing and agriculture; in industry, the food sector dominates with 55 of 89 firms.