Mitromorpha alphonsiana is a species of sea snail, a marine gastropod mollusk in the family Mitromorphidae.

The middle of the whorls is ornated with white and yellow dots, alternating on the ribs, below two series of granules, cut by subsutural striae.

Those two rows of dots on the superior part have a violet-rose color only on the first two whorls.

The longitudinal ribs are dense and are crossed by two transverse striae on each whorl, subsutarally sulcate and decussate by small lirae.

The convex outer lip is incrassate and sinuate at the suture and has a sharp margin.