Roberto Rastapopoulos is a fictional character, the arch-nemesis of Hergé's boy reporter Tintin, appearing in a number of the comic strip albums The Adventures of Tintin. Mustachioed and swarthy, the Greek-American film director and tycoon first appeared in Cigars of the Pharaoh, initially as a seemingly sympathetic character. It was not until the denoument of The Blue Lotus, the follow-up to Cigars of the Pharaoh, that Rastapopoulos was revealed to be the head of the sinister opium-smuggling ring against which Tintin had been pitting his wits for two books.

Rastapopoulos subsequently resurfaced as a slave trader in The Red Sea Sharks (under the alias of the Marquis di Gorgonzola) and kidnapped the millionaire Lazslo Carreidas in Flight 714. In the latter album Hergé had him dress in a disgusting pink cowboy suit, thus transforming him from a menacing figure into a ridiculous one, an example of the way in which Hergé deliberately subverted his own fictional universe in the later Tintin books. Flight 714 ends with Rastapopoulos being abducted by an alien craft, the last that is seen of him.

Rastapopoulos also appeared in the lamentable Tintin and the Lake of Sharks, an album adapted from an animated feature of the same name, and into which Hergé had no creative input. It is not considered to be part of the Tintin canon.

Rastapopoulos first appeared in 'Tinin in America', where he is seen sitting left of Tintin, and celebrating Tintin's successful adventure in America during a Gala dinner.