Ray County[a] (Persian: شهرستان ری) is in Tehran province, Iran.

[8] After the 2016 census, the village of Qaleh Now-e Khaleseh was elevated to the status of a city.

[11] The 2016 census measured the population of the county as 349,700 in 96,996 households.

[2] Ray County's population history and administrative structure over three consecutive censuses are shown in the following table.

According to the information of the State Meteorological Organization of Tehran province, the long-term average annual rainfall of Ray County is around 168.6 mm.