This weaver is very widespread and found in a wide range of habitats, including shrubland, savanna, grassland, open woodland, inland wetlands and semi-desert areas.

The southern masked weaver is 11–14.5 cm (4.3–5.7 in) long with a short, strong, conical bill and pinkish brown legs.

The adult male in breeding plumage has a black face, throat and beak, red eye, bright yellow head and underparts, and a plain yellowish-green back, The female has a pinkish-brown bill, brown or red-brown eye and is dull greenish-yellow, streaked darker on the upper back.

Males have several female partners, and build a succession of nests, typically 25 each season.

The southern masked weaver lays eggs of a various colour and this helps it to evade parasitisation by cuckoos because the cuckoo has no way of knowing what kind of eggs are inside the weaver's nest until it has entered the nest to attempt to lay one itself.