Psah Chas (Khmer: ផ្សារចាស់, literally "Old Market"), is a market in the city of Siem Reap in northern Cambodia. Not to be confused with the similarly named Psah Chas in Phnom Penh that is geared toward locals, this open air market in the south of the city caters to locals and tourists alike. The market is such a fixture in Siem Reap that most businesses give their address in relation to Psah Chas.
The market is popular with tourists in the city and sells souvenirs but it is also known for its variety of Cambodian cuisine, and has a number of food stalls which sell a variety of rices, dried fish and pork sausages, vegetables and fruits, and a Cambodian specialty Prahok, a type of fermented fish paste. Some stalls sell baguettes and spiced frogs, which is believed to be a relic of French colonialism in the area. Other stalls cook up various Khmer soups and red chili slices and peanuts.