剑鱼或称剑旗鱼，是一种大型的掠食性鱼类，为辐鳍鱼纲鲈形目鲭亚目剑旗鱼科剑旗鱼属的唯一一个物种。

本鱼分布于全球的热带和温带海域。

Swordfish (Xiphias gladius; from Greek ξίφος: sword, and Latin gladius: sword), also known as broadbills in some countries, are large, highly migratory, predatory fish characterized by a long, flat bill. They are a popular sport fish of the billfish category, though elusive. Swordfish are elongated, round-bodied, and lose all teeth and scales by adulthood. These fish are found widely in tropical and temperate parts of the Atlantic, Pacific, and Indian Oceans, and can typically be found from near the surface to a depth of 550 m (1,800 ft). They commonly reach 3 m (9.8 ft) in length, and the maximum reported is 4.55 m (14.9 ft) in length and 650 kg (1,430 lb) in weight.