Haplopharynx is a genus of small, free living marine flatworms found in the North Atlantic and the Mediterranean.

The following species are recognized in the genus Haplopharynx: Subterminal mouth leads to the simple pharynx, which subsequently continues as an intestine with terminal anal pore.

Variable number of glands producing rhabdites open at the surface of proboscis.

Male copulatory organ is equipped with hard, sclerotised stylet and set of needles.

Egg is entolecithal and show spiral cleavage pattern.