鲤科是鲤形目下种类最多的一个科，包括210属2010种。中国共有132属532种和亚种，其中包括鲤鱼、鲫鱼等常见鱼类。此科鱼的特征是口部有须。有咽齿没脂鳍。鲤科一族在北美，非洲，欧亚有着密切的联系。最大的鲤鱼—巨暹罗鲤（Catlocarpio siamensis）,可以长到3米长。在北美分支中的尖头叶唇鱼（Ptychocheilus lucius）单体记录为1.8米长，45千克。

与之相对的，有很多种类的体长不足5厘米。截至2008年，最小的淡水鱼名为Danionella translucida，发育成熟后体长仅为12毫米。鲤科的所有成员均为卵生，大部分不保护他们的卵。但是，有一些种类建鱼窝或护卵。鳑鲏类的鱼会将卵产于贝类体内，新生的小鱼直到有能力生存后才离开寄主。

Cyprinidae is the family of freshwater fishes, collectively called cyprinids, that includes the carps, the true minnows, and their relatives (for example, the barbs and barbels). Also commonly called the "carp family," or "minnow family," Cyprinidae is the largest known fish family and the largest vertebrate animals family in general, with about 3,000 living and extinct species in about 370 genera. The family belongs to the ostariophysian order Cypriniformes, of whose genera and species the cyprinids make more than two-thirds. The family name is derived from the Ancient Greek kyprînos (κυπρῖνος, "carp").