The Motion Picture Association of America (MPAA) is an American trade association that represents the six big Hollywood studios. It was founded in 1922 as the Motion Picture Producers and Distributors of America (MPPDA) to advance the business interests of its members. In its formative years it took on the role of devising guidelines for film content which resulted in the creation of the Production Code, and currently administers the MPAA film rating system. Every Nickelodeon Movies film assigned a certain rating, based on their content. Violence, sexual content, substance abuse, and strong language are all things that are taken into consideration when rating a film. There are currently five ratings: G, PG (previously GP), PG-13 (adopted in 1984), R, and NC-17 (previously X). If a film has not yet been assigned a final rating, the label "THIS FILM IS NOT YET RATED" is used in TV spots, advertisements, and the official websites of the films. For more information about the MPAA rating system, see below.
- Not a single film from the Nickelodeon Movies film library has ever received an R-rating or an NC-17-rating from the MPAA, since the studio is marketed as a family film studio.
- The term "thematic elements/material" was used to highlight elements of a film that do not fit into the traditional categories such as violence, sex, drug use and language, but may involve some degree of malcontent. Harriet the Spy, Hey Arnold!: The Movie, Lemony Snicket's A Series of Unfortunate Events, Mad Hot Ballroom, The Spiderwick Chronicles and Hotel for Dogs used this term in their film rating.
- In 2013, the MPAA has redesigned their rating icons, as part of the "Check the Box" campaign (see poster below). The "new" ratings have higher emphasis on the reasons that each film got its rating in an effort to give parents as much information as possible when choosing the right movies for their children.