Subspace turbulence is a subspace anomaly which causes severe disruption in subspace.

In 2153, during a ruse to gain information from the Xindi-Primate Degra, Captain Jonathan Archer had the pretend shuttle they were in experience subspace turbulence in order to make the deception feel as real as possible. (ENT: "Stratagem")

In 2372, while hiding from Vidiian patrols in a plasma drift, the USS Voyager encountered severe subspace turbulence resulting in power failures across the ship. The situation was later discovered to be the result of a subspace divergence field which had created two Voyagers. Eventually, a solution was found when one of the ships initiated its self-destruct, closing the rift for good. (VOY: "Deadlock")