Wolfsbane is a fictional character, a superhero in Marvel Comics' universe. She is a mutant with the superhuman ability to transform into a wolf or a hybrid wolf/human form.

Wolfsbane (real name Rahne Sinclair (Rahne is pronounced "Rain")) first appeared in Marvel Graphic Novel #4: The New Mutants. Rahne is a Scottish citizen who was a ward of Moira MacTaggert. She was recruited by Professor X to join the original New Mutants, and remained with that team for much of its existence. During the "X-Tinction Agenda" storyline in Genosha, she was mentally bonded to Havok, and was subsequently manipulated by the Shadow King; this led to her joining X-Factor. Some time after her mental damage from the Genoshan bonding process was undone, she returned to MacTaggert's base on Muir Island and joined Excalibur.

She is currently a teaching assistant at the Xavier Institute, while working part-time for Jamie Madrox's detective agency, and is in a secret relationship with Elixir.

Wolfsbane is featured as a minor X-Man character in X-Men: Evolution.