The San Simon Valley is a broad valley east of the Chiricahua Mountains, in the northeast corner of Cochise County, Arizona and southeastern Graham County, with a small portion near Antelope Pass in Hidalgo County of southwestern New Mexico.

[1] The foot of the valley is at the northern end where the ephemeral San Simon River, that flows northwest through the valley to Safford in Graham County, enters the Gila River.

The head of the valley, 31°39′36″N 109°16′59″W / 31.66000°N 109.28306°W / 31.66000; -109.28306, is at the junction of the two valleys, along the divide between the south side of Rustler Canyon Creek watershed and Paramore Crater just south of the town of Apache.

The White Mountains lie north of the northern end of the valley.

The San Simon Valley is noted for the ceramics of native American Indians called the Roosevelt Red Ware, one type being named for a site in the valley, the Nine Mile Polychrome.