The genus Neptis established by Hübner in 1819 is invalid; see Vila (butterfly). Neptis is a large genus of butterflies of Old World tropics subtropics. They are commonly called sailer butterflies or sailers, or more precisely typical sailers to distinguish them from the related blue sailer (Pseudoneptis).

The head is rather broad and moderately hairy on the forehead. The eyes are large and prominent. The palpi are short, acute, slender, hairy, and do not rise above the level of the forehead. The antennae are moderately long, terminating in an elongate, gradually-formed club, flattened on its upper surface. The thorax is not robust and it is as broad as the head and slightly hairy posteriorly. The wing characters are: forewings elongate, rather truncate; costa only slightly arched; apex not acute, but well marked; hind margin slightly convex and sinuated; anal angle distinct; inner-margin convex near base, slightly concave about middle. Hindwings large, rounded; costa strongly arched; hind margin moderately dentate; inner margins only slightly convex, not covering posterior portion of the abdomen. Upperside patterning consists of white spots and bars (some species have orange or yellow bars) on a black ground colour. Underside patterns are yellowish to reddish brown, alternating with white bands The legs are rather short and stout. The abdomen is slender, much compressed and rather elongate. The head of the larva is very large and bifid on its summit. There is a pair of downy, elongate, tubercular processes, projecting laterally, on both the second and third segments—those on the third segment are much longer. There is an upright pyramidal process on the penultimate segment and the body is attenuated posteriorly. The pupa is strongly curved (thick in central portion). The head is deeply bifid.

About 65 species occur in the Afrotropical realm, over 40 in the Palearctic realm 6 in the Australasian realm and about 50 occur in the Indomalayan realm.

Larval food plants come from the families Fabaceae, Rhamnaceae, Euphorbiaceae, Polygonaceae, Sapindaceae, Urticaceae and Connaraceae. Adults have a "sailing" flight flapping their wings and then gliding. They frequently perch and visit flowers for nectar and damp patches where they imbibe salts and other nutrients. Adult uppersides exhibit disruptive coloration, This species has been observed to make sounds whose function has not been established.

Neptis are allied to Pantoporia, in which the white wing markings are replaced by orange and to Athyma resemble Neptis but have more triangular forewings. The type species of the genus is Papilio aceris Esper.