Simon Grady is a character in Cube 2: Hypercube played by Geraint Wyn Davies.

He is a private detective hired to locate a young woman named Becky Young who is missing. At the end of the movie, Simon goes insane after losing the grip of reality; he understands that the Cube holds alternate dimensions and contains parallel timelines where he finds himself dead and murdering others. Simon ends up killing at least 4 Jerries and 3 Beckys (who originate from parallel universes) and it is heavily implied he resorts to cannibalism. He is killed by Kate after they end up in hand-to hand combat.