Collo (Arabic: القل, romanized: al-Qull), known as Chullu in antiquity, is a port town in the Skikda Province in northeastern Algeria, and forms part of the Collo Massif region.

In Roman times, Collo was a city in the province of Numidia, called Chullu.

[1][2][3] In 1282, king Peter III of Aragon led an expedition to Collo, in proclaimed support of a rebellion against the ruler of Tunis.

The rebellion had collapsed before Peter arrived, but he kept his army there for several weeks until, in the wake of the Sicilian Vespers, envoys from Sicily came to Collo to offer him its throne.

[4] In 1833, the Roman diocese was nominally revived as a titular see of the lowest (episcopal) rank.