The Mutant Phase is a Big Finish Productions audio drama based on the long-running British science fiction television series Doctor Who.

It forms the third serial in the Dalek Empire arc, following on from events in The Genocide Machine and The Apocalypse Element.

The arc concludes in The Time of the Daleks.

A director's cut of the first episode was included with the Doctor Who Magazine bonus CD story Cuddlesome.

The Fifth Doctor and Nyssa discover that even the Daleks have foes that they fear as a paradox threatens to destroy the universe... but are the Daleks the threat or the cure?