Profundisepta profundi is a species of sea snail, a marine gastropod mollusk in the family Fissurellidae, the keyhole limpets.

[2] The height of the shell is shorter than its width and a sculpture of granular riblets radiate from the apex, both of which help distinguish the species from the related P. alicei, which has a smooth shell taller than it is wide.

[2] Mosquera et al. (1981) and Mosquera (1983) misidentified a Puncturella agger specimen as belonging to this species (then called Puncturella profundi).

[3] While P. agger shares the radial rows of granules with Profundisepta profundi, it is distinct in that there is a slit, rather than a hole, near the top of the shell, stretching from the apex to the anterior edge.

[2] This species is distributed in the Northern Atlantic Ocean along Iceland and Greenland.