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.
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.
Endangered animals live in the area, including one endemic species, the desert pupfish.
It was named by British explorer Robert William Hale Hardy and noted in his Travels in the Interior of Mexico in 1825 – 1828 originally published in London in 1829.
Hardy thought it marked the entrance to the Colorado River.