Penion lineatus is a species of medium-sized marine snail or whelk, belonging to the true whelk family Austrosiphonidae.

[1][2][3] It was described in 2018.

[2] Adult shells are between 68 mm and 172 mm in length.

The shell protoconch is cream coloured and the teleoconch is covered in yellow or brown bands.

[2] Penion lineatus is endemic to waters surrounding the Three Kings Islands and Cape Reinga north of mainland New Zealand.