Agente 3S3: aporto per l'inferno or Agent 3S3:port to Hell is a 1965 Italian adventure-eurospy film directed by Sergio Sollima, here credited as Simon Sterling. This is the first chapter in the Sollima's spy film trilogy, and inaugurated the film series of the Agent 3S3 played by George Ardisson. It is also the first Sollima's full-length film, after the episode he filmed in L'amore difficile three years before.

Location filming includes Spain, Rome, Beirut and Vienna. This was followed by the sequel Agent 3S3, Massacre in the Sun (1966) also directed by Sollima that was shot back to back.