San Tan Valley derives its name from the nearby San Tan Mountains. The origin of the name San Tan is disputed, with suggestions ranging from a corruption of the name Santa Ana to the last name of George Santan, prior postmaster in nearby Gila County. Previously referred to as San Tan Heights, San Tan Foothills, Greater San Tan and simply the San Tan Area. The area consists largely of master planned communities, such as Johnson Ranch, Ironwood Crossing, Pecan Creek South, San Tan Heights, Skyline Ranch, Copper Basin and Circle Cross Ranch.
Situated east of the San Tan Mountains, the community is located in the Sonoran Desert. As such, it experiences the hot, arid summers and moderate winters that typify the area.