A souq or souk (Arabic: سوق‎ sūq, also spelled soq, souk, esouk, suk, sooq, souq, or suq) is an open-air marketplace or commercial quarter in an Arab, or Berber city. A souk or souq entails the concept of a free-market where vendors can command the going market price for their products. The term is often used to designate the market in any Arabized or Muslim city, but in modern times it appears in Western cities too. It may also refer to the weekly market in some smaller towns where neutrality from tribal conflicts would be declared to permit the exchange of surplus goods. In Modern Standard Arabic the term refers to markets in both the physical sense and the abstract economic sense (e.g., an Arab would speak of the souq in the old city as well as the souq for oil, and would call the concept of the free market السوق الحرّ as-sūq al-ḥurr).

A souk is an open-air marketplace. Historically, souqs were held outside of cities in the location where a caravan loaded with goods would stop and merchants would display their goods for sale. Souqs were held when there was a caravan or more available. At that time, souqs were more than just a market to buy and sell goods; they were also major festivals and many cultural and social activities took place in them.