Inner Sanctum is a 1948 American film noir directed by Lew Landers based on the Simon & Schuster book series of the same name and the Inner Sanctum Mystery radio series. A previous film series of the show had been produced by Universal Pictures until 1945. It is the first and only film of M.R.S. productions, the initials of Richard B. Morros, Samuel Rheiner and Walter Shenson.