Pseudodaphnella oligoina is a species of sea snail, a marine gastropod mollusk in the family Raphitomidae.

(Original description) The shell is of medium size, rather thin, lanceolate, turreted, with a sloping shoulder, perpendicular periphery, and an excavate base.

From the shoulder to the basal angle are five cords, which override the ribs and thus enclose a series of oblong and nearly uniform meshes.

The basal furrow is spaced as if a spiral of regular sequence to the rest were omitted.

This species has a general resemblance to Kermia spelaeodea Hervier, 1897 (synonym of Pseudodaphnella infrasulcata (Garrett, 1873)) from New Caledonia, but is smaller, thinner, less cylindrical, and with fewer radials and spirals, resulting in larger meshes in the sculpture.