海龙鱼目（学名：Syngnathiformes）也称海龙目，为辐鳍鱼纲的一目，除了腹鳍和尾鳍有部分分支鳍条外，背鳍、臀鳍及胸鳍均不分支。多数身体细长。吻呈长管状；口小，位于吻端。鳃呈退化现象。鳔无鳔管。

现一般分为7科：

在分类上有时将海龙鱼目划归为刺鱼目下的“海龙鱼亚目”（Syngnathoidei）。

The Syngnathiformes are an order of ray-finned fishes that includes the pipefishes and seahorses.

These fishes have elongated, narrow, bodies surrounded by a series of bony rings, and small, tubular mouths. Several groups live among seaweed and swim with their bodies aligned vertically, to blend in with the stems.