Eucithara novaehollandiae, common name the thick-lipped mangelia, is a small sea snail, a marine gastropod mollusk in the family Mangeliidae.

The color of the shell is yellowish white or light brown, banded with pale chocolate, crossed with numerous obscure fine white lines.

The whorls are rounded at the upper part and longitudinally closely ribbed.

The shell has a lead color or is banded with lead color, crossed with numerous obscure fine white lines.

[3] This marine species occurs off the Philippines, Polynesia, New Caledonia, Western Australia and Mozambique.