Heterocithara bilineata is a species of sea snail, a marine gastropod mollusk in the family Mangeliidae.

[1] (Original description) The shell is ovately turreted, moderately solid, pale straw-colour or light brown, nearly white around the aperture and at the base, with a narrow brown band just below the suture, and a second between the periphery and the base of the body whorl.

The shell contains 6 whorls , angulate at the upper part, coarsely longitudinally ribbed and transversely ridged.

The outer lip is arcuate, contracted towards the base, and thickened behind.

[2] This marine species is endemic to Australia and occurs off New South Wales and Victoria.