The southern sand darter (Ammocrypta meridiana) is a species of freshwater ray-finned fish, a darter from the subfamily Etheostomatinae, part of the family Percidae, which also contains the perches, ruffes and pikeperches.

It can be told apart from the scaly sand darter by the lack of any dark bands on the dorsal, anal or caudal fins, that the blotches along the lateral line are lengthened horizontally and that there are no tubercles on the anal fin when breeding.

It is more completely covered in scales than the Eastern sand darter, the tip of its snout is usually coloured.

[2] The Southern sand darter is found in the rivers draining into Mobile Bay in Alabama and Mississippi.

[4] The Southern sand darter was first formally described in 1975 by the American biologist James D. Williams with the type locality given as Cedar Creek on Alabama State Route 41 near Sardis, Alabama.