Biel will appear as guest in an upcoming episode of the Fox comedy as a rival of Jess in a wedding. Her character is described as "the hottest scientist in the world".
In the episode Jess (Deschanel) vies for the attention of a cute guest but she faces competition from Biel's character Kat, said the Hollywood Reporter.
Biel has previously starred on seven seasons of '7th Heaven'. She next appears in the movie 'Shiva and May'.