Collo (Arabic: القل‎) is the capital, and one of three municipalities, of Collo district in Skikda Province, Algeria, and a Catholic titular episcopal see under its Roman name Chullu. In 1998 it had a population of 27,800 In Roman times it was a city in the province of Numidia, called Chullu. At the joint Conference of Carthage that in 411 brought together Catholic and Donatist bishops of Roman Africa, Chullu was represented by the Catholic bishop Victor and the Donatist Fidentius