Chatuchak (or Jatujak; Thai: จตุจักร) weekend market in Bangkok is the largest market in Thailand and the world's largest weekend market. Frequently called J.J., it covers over 35 acres (0.14 km²) and contains upwards of 15,000 stalls. It is estimated that the market receives 200,000 visitors each day. Most stalls only open on Saturdays and Sundays though Jatujak Plaza, the western section is open daily. In the north west corner is the J.J. Mall, with three floors of assorted oddments as well as eateries.

The market offers a wide variety of products including household items, clothing, Thai handicrafts, religious artifacts, collectibles, foods, and live animals. For tourists, there are a number of onsite companies who will send purchases abroad. Tourists also find Chatuchak a prominent place to find skilled Thai iced tea makers practicing their trade.