长尾毛丝鼠（英文：Long-tailed Chinchilla，学名：Chinchilla lanigera）又称绒毛丝鼠、长尾栗鼠、毛丝鼠、绒鼠等名称。主要分布为南美洲安第斯山脉上的高原，范围从智利北部至秘鲁南方。牠的皮毛十分柔软细滑，一个毛细孔有50根毛，因此体毛看起来较为蓬松，体重约500～800公克，体长22～38公分，所以身体看起来较胖，尾巴较长，长约7～15公分，加上牠的耳朵竖直，如似宫崎骏作品龙猫。早期猎人为求长尾毛丝鼠的皮毛，遭大量的捕猎之后，如今野生长尾毛丝鼠已所剩不多，据信目前大约只剩下千只左右，归类为濒危物种，被CITES列入附录一等级的保育名单中。

The long-tailed chinchilla (Chinchilla lanigera), also called the Chilean, coastal, common chinchilla, or lesser chinchilla, is one of two species of rodents from the genus Chinchilla, the other species being Chinchilla chinchilla. Wild populations of C. lanigera occur in Aucó, near Illapel, IV Región, Chile (31°38’S, 71°06’W), in Reserva Nacional Las Chinchillas and in La Higuera, about 100 km (62 mi) north of Coquimbo (29°33’S, 71°04’W) Chilean chinchillas were reported from Talca (35°30’S), Chile, reaching north to Peru and eastward from Chilean coastal hills throughout low mountains. By the mid-19th century, Chilean chinchillas were not found south of the Choapa River.