阔鼻小目（又称新世界猴；学名：Platyrrhini）是产于中美与南美的四科灵长目动物，包括卷尾猴科、青猴科、僧面猴科和蜘蛛猴科。新世界猴与旧世界猴合称为猴。

新世界猴与旧世界猴的主要区别在于鼻部。新世界猴的鼻部软骨间隔很宽，鼻孔开向侧方，鼻孔间距较宽，旧世界猴的鼻间距则很窄；此外，新世界猴有12个前臼齿，而旧世界猴与猿类一样只有8个。

New World monkeys are the five families of primates that are found in Central and South America and portions of Mexico: Callitrichidae, Cebidae, Aotidae, Pitheciidae, and Atelidae. The five families are ranked together as the Platyrrhini parvorder and the Ceboidea superfamily, which are essentially synonymous since Ceboidea is the only living platyrrhine superfamily. Platyrhini means flat-nosed, and their noses are flatter than those of other simians, with sideways-facing nostrils. Monkeys in the family Atelidae, such as the spider monkey, are the only primates to have prehensile tails. New World monkeys' closest relatives are the other simians, the Catarrhini ("down-nosed," comprising Old World monkeys and apes). New World monkeys descend from African simians that colonized South America, a line that split off about 40 million years ago.