Warden Delaire is a member of the Parole Board at the New Jersey Prison where House was imprisoned. Apparently, he chairs the board and has the most influence over their decisions. He was portrayed by actor Michael Pare.
He has the power to release prisoners on parole according their behavior. He also can deny parole if he thinks it's necessary. In Twenty Vicodin, after House makes fun of his system, he declares House will be paroled in 5 days if he stays out of trouble.
Due to the forceful way he speaks to House, his personality appears to be very serious.