Hydrus (disambiguation)

Hydrus is a small constellation in the southern sky.

Hydrus may also refer to:
 * Hydrus (Chinese astronomy), constellations recognized in China
 * Hydrus (legendary creature), a creature from Medieval bestiaries
 * Hydrus (roller coaster), a Gerstlauer Euro-Fighter roller coaster at Casino Pier
 * Hydrus (software), a software suite for simulating subsurface water flow
 * SS Hydrus, a Great Lakes freighter
 * The 7th Colossus from Shadow of the Colossus