Stenocactus coptonogonus is a species of cactus native to the deserts of Mexico.

Stenocactus coptonogonus is a small (7–10 cm (2.8–3.9 in)) globose to subglobose in habit.

Unlike other members of the genus Stenocactus it lacks the characteristic numerous wavy ribs instead having 10-15 stout, thick, triangular ribs 1.5 cm (0.59 in) high, 5 mm (0.20 in) or more in width.

[2] Its flowers are white with purple or violet mid-veins 3–4 cm (1.2–1.6 in) in diameter.

Stenocactus coptonongonus is found in Zacatecas, San Luis Potosí, Guanajuato, and Hidalgo areas of Mexico.