硬骨鱼是鱼类的一个主要类别，大部分鱼类属于硬骨鱼类。

骨骼多为硬骨，身体被硬鳞、圆鳞或栉鳞，有时裸露无鳞；无鳃裂，外被一骨质鳃盖；一般具有鳔。大多是体外受精，卵生，少数为卵胎生。

硬骨鱼类主要分为如下两大类：

从支序分类的角度，硬骨鱼应该是硬骨脊椎动物(Euteleostomi)的并系群，包括辐鳍鱼和肉鳍鱼以下的硬骨脊椎动物构成一个单系群。

Osteichthyes /ˌɒstiːˈɪkθi.iːz/, popularly referred to as the bony fish, is a diverse taxonomic group of fish that have skeletons primarily composed of bone tissue, as opposed to cartilage. The vast majority of fish are members of Osteichthyes, which is an extremely diverse and abundant group consisting of 45 orders, and over 435 families and 28,000 species. It is the largest class of vertebrates in existence today. The group Osteichthyes is divided into the ray-finned fish (Actinopterygii) and lobe-finned fish (Sarcopterygii). The oldest known fossils of bony fish are about 420 million years ago, which are also transitional fossils, showing a tooth pattern that is in between the tooth rows of sharks and bony fishes.