蝇虎科或跳蛛科（学名：Salticidae），是蜘蛛目的一科，也是蝇虎总科的唯一科。

全世界约有跳蛛5000种，中国有300种以上。中国广东粤东地区常见为灰色，背面有黑色斑纹，全身绒毛。

跳蛛有8只单眼，体型较小，最小的只有几十毫米。因其捕猎物的方式，及主要以苍蝇为食，俗称苍蝇老虎；又因视力发达，善于跳跃，亦称跳蛛。潜近猎物时，先逐步靠近，再跳到猎物身上。在天花板上倒行时亦可跳跃捕食。跳蛛一般不织网，但能吐丝，因从树上等高处摔下危险，预备跳时先帖上一根丝，就像爬山者用岩钉及绳子防止坠落。

蝇虎蜘蛛头胸部比起其他科是方形的。（见图一。）头胸部上的八个眼睛，其中两个平常比别的都大。（见图二。）

The jumping spider family (Salticidae) contains over 500 described genera and over 5,000 described species, making it the largest family of spiders with about 13% of all species. Jumping spiders have some of the best vision among arthropods and use it in courtship, hunting, and navigation. Although they normally move unobtrusively and fairly slowly, most species are capable of very agile jumps, notably when hunting, but sometimes in response to sudden threats or crossing long gaps. Both their book lungs and the tracheal system are well-developed, and they use both systems (bimodal breathing). Jumping spiders are generally recognized by their eye pattern. All jumping spiders have four pairs of eyes with one pair being their particularly large anterior median eyes.