Acanthocalycium leucanthum is a species of flowering plant in the cactus family Cactaceae from Argentina.

The single thick, brown central spine is curved upwards and 5 to 10 cm (2.0 to 3.9 in) long.

The long, funnel-shaped, white, occasionally slightly pink flowers appear on the upper parts of the shoots and open at night.

[2] Acanthocalycium leucanthum is widespread in northwest to central Argentina from sea level to altitudes of 1000 meters.

[3] The specific epithet leucantha is derived from the Greek words leukos for 'white' and anthos for 'flower' and refers to the flower color of the species.