Nong Chok (Thai: หนองจอก, pronounced [nɔ̌ːŋ t͡ɕɔ̀ːk]) is one of the 50 districts (khet) of Bangkok, Thailand. It is bounded by other districts (from north clockwise): Amphoe Lam Luk Ka of Pathum Thani Province, Amphoe Bang Nam Priao and Amphoe Mueang Chachoengsao of Chachoengsao Province, Lat Krabang, Min Buri and Khlong Sam Wa of Bangkok. It is the biggest and the most sparsely populated district of Bangkok.
The district was established as an amphoe in 1897 during the reign of King Chulalongkorn. The original settlers were Muslims relocated from southern Thailand. In 1902, it became an amphoe of the newly setup Min Buri Province. Due to economic hardship during 1930-31, Min Buri Province was disbanded in 1931 and Nong Chok was transferred to Chachoengsao Province. However the administration was moved under Bangkok the next year due to inconvenience of travel between Nong Chok and Chachoengsao. As of 2006, about 75% of the population were Muslims while 22% were Buddhists. The name Nong Chok means water lettuce (Pistia stratiotes) swamp.