Six new species of Hesionura are described from estuarine and continental shelf bottoms off southern and south-eastern Brazil. Hesionura laubieri (Hartmann-Schröder, 1963) is redescribed based on newly collected material. Hesionura ceciliae sp. nov. is diagnosed by conical ventral cirri on anterior and median segments, with tapered distal ends, and by four bidentate chaetae throughout the body, except in the last segments, which have an additional supracicular unidentate chaeta. The ventral cirri on median parapodia of Hesionura biformata sp. nov. are more than 1.5 times as long as the neuropodial lobes, abruptly tapering on posterior segments; posterior parapodia have one bidentate and two unidentate subacicular chaetae. Hesionura variodentata sp. nov. has conical tentacular ventral cirri, anterior and median parapodia with first dorsal chaeta tridentate and the other three bidentate, and posterior parapodia with four chaetae, the three most dorsal bidentate and the most ventral unidentate. The ventral tentacular cirri of Hesionura carioca sp. nov. are cylindrical and elongated, with tapered distal ends; dorsal cirri are oval, and posterior parapodia have one tridentate, three bidentate and one unidentate chaetae. Adults of Hesionura longissima sp. nov. reach up to 21 mm, a length not previously been reported for the otherwise meiofaunal genus Hesionura; their first supracicular chaeta is quadridentate and dorsal and ventral cirri are rounded in reproductive stages. Hesionura lupina sp. nov. has cylindrical and elongated ventral tentacular cirri, with tapered distal ends, oval dorsal cirri, cylindrical ventral cirri, and posterior parapodia with five bidentate chaetae.