Paranoiac is a 1963 suspense film from Hammer Films directed by Freddie Francis and starring Janette Scott, Oliver Reed, Sheila Burrell, and Alexander Davion.

Simon Ashby is a wealthy psychotic who is is coddled by his aunt in their palatial mansion outside of London. One day, Ashby's long lost brother mysteriously arrives at the house, but events prove that he is an impostor, sent by Keith Kossett, son of the attorney for the family estate, who has been dipping into the family trust fund. Written by Wheeler Winston Dixon