Bahia Adair or Adair Bay is a bay at the northern end of the Gulf of California in the municipality of San Luis Río Colorado in the state of Sonora in Mexico. It is 40 kilometers from east to west and 15 kilometres from north to south. It contains basins with sizable deposits of salts. The shore area consists of 42,430 hectares (104,800 acres) of wetlands which were designated a conservation zone under the Ramsar Convention in 2009. There are three different habitats: the wetlands, artesian wells, and the salt pans. Endangered animals live in the area, including one endemic species, the desert pupfish.