Milan Stilton is a spoiled and self-centered hotel heiress who appeared as a villain in the Season 4 episode, "Evil Heiress Much?". Milan was the fifth richest person in the world, after Chester Bates, Kimberly Kelly, Helena Simms, and Thomas Hansen. However, she wasn't satisfied with being anything less than number one, and since she was no good at making money (which she said so herself), she claimed the only way she could be the richest person in the world was to get rid of the competition. Milan used her robotic dog, Fufu, to kidnap Thomas, Helena, Kimberly, and Chester.
After the first three richest people were kidnapped, and not knowing she was the culprit, Jerry Lewis sent Samantha, Clover, and Alex to protect Milan, although Sam complains that since the top three richest people were kidnapped, it would've made more sense to protect the fourth richest person. Jerry explains that Chester Bates had told them that he wouldn't need them to protect him, because he was confident that his security system would be able to do so. Milan accepted the offer grudgingly, presumably to throw suspicion off her. When the spies discovered the truth, Milan had her robo-dog knock them out and she imprisoned them with the others. After escaping Milan's death trap, the spies destroy the robot dog and capture Milan. Clover jokes that Milan's sentence is 150 years.
- Milan's clothes, attitude, other behaviors, pet dog and even her name are all parodies of the real-life hotel heiress, Paris Hilton.
- Milan and Paris are two of the largest cities in Europe, and 2 of Europe's (and the world's) fashion capitals (Paris is the fashion capital of the France and the actual capital, while Milan is the fashion capital of Italy but Rome is the actual capital). And "Stilton" is just "Hilton" with an "St"' instead of an "H".
- Her skinny figure is a reference to the stereotype of socialites, female models, beauty contestants, female dancers, and actresses all having thin bodies.
- She's obsessed with diamonds and the color pink (especially pink diamonds).
- Her walk-in closet is apparently bigger than Clover's bedroom.
- A look-alike is seen in "Astro-Not" and "Pageant Problems".
- She made a cameo in "Totally Spies! The Movie".
- She is apparently an airhead since she forgot she was wearing the Emerald Tracking Pendant.