Turridrupa nagasakiensis is a species of sea snail, a marine gastropod mollusk in the family Turridae, the turrids.

The ribs are rounded and oblique, sixteen on the penultimate whorl and do not quite attain to the suture, but become obsolete in the sloping concavity above.

The outer lip is thin, much produced and arcuated at the middle, broadly and deeply notched a little below the suture, and with a second shallow sinuation near the base.

The columella is suberect, smooth, coated with a thin callosity, terminating above at the sinus in the form of a tubercle.

[2] The yellowish brown shell is closely sculptured by longitudinal numerous ribs and spiral striae.