Leonard, 39, will play James Finnigan, a community college psych professor whose pull towards Norma (Vera Farmiga) slowly chips away at his carefully constructed house of cards, reported Aceshowbiz.
The gig reunites the actor and Farmiga, who played husband and wife in 2011's indie flick 'Higher Ground' directed by the actress.
The third season of the 'Psycho' prequel series will premiere in March 2015.