According to multiple sources, including Mens Health, Polygon, Game Rant, CBR, and GamesRadar, there are several movies and shows that are recommended to watch before seeing The Marvels. However, the consensus is that it is not necessary to watch anything before seeing the movie, as long as you have watched Avengers: Endgame. If you want to be more familiar with the characters and their backstories, it is recommended to watch Captain Marvel, as it is a direct sequel to that movie. Additionally, watching the Disney+ shows WandaVision and Ms. Marvel can provide more context for the characters of Monica Rambeau and Kamala Khan, respectively. Secret Invasion is also mentioned as a show that could be helpful to watch, but it is not considered essential. Ultimately, it is up to personal preference and familiarity with the MCU.