Atrophaneura nevilli Byasa nevilli, the Nevill's windmill, is a butterfly found in India that belongs to the windmills genus (Byasa), comprising tailed black swallowtail butterflies with white spots and red submarginal crescents.
North east India (Assam), Myanmar (Shan states) and western China.
In appearance it is similar to the great windmill (Byasa dasarada), but is smaller.
The male differs as follows: the subterminal series of lunules on the hindwing are crimson or vermilion red, never white or partly white as in B. d. ravana; sexual abdominal fold within white, not blackish brown; the subterminal red lunule in interspace 3 very often missing.
From B. d. ravana female it differs in the complete absence of the white discal spots in interspaces 1, 2, 3 and 4.