Xanthodaphne leptalea is a species of sea snail, a marine gastropod mollusk in the family Raphitomidae.

(Original description) The shell is of moderate size, rather stout, very thin and fragile, delicately tinted with brown below the chestnut-brown tip.

The outer lip is badly broken, but, judging by the lines of growth, sweeps well forward from the posterior sinus, which is as wide as the subsutural band, and deepest next the suture.

The columella is very straight with a narrow, very thin, closely adhering layer of enamel.

The subsutural band is broad, oblique, crossed by numerous very delicate curved riblets and lines of growth, most conspicuous just at the suture.