According to Entertainment Weekly, the actress the world knows as Meg Ryan was born Margaret Mary Emily Anne Hyra. The actress decided to shorten her first name and use the maiden name of her maternal grandmother when joining the Screen Actors Guild after she decided to pursue acting as a career.
Many of Hollywood's biggest stars join SAG-AFTRA in their careers, as it is a labor union that represents performers and others in the industry and protects their rights. You can either "earn" the card by making a name for yourself in the industry, according to the site, or pay an initiation fee of around $3,000.
By joining SAG, there's also a stipulation that if your name is already being used by an actor already in the union, you can't use it as your professional name, according to Actors' Sound Advice. Instead, you're required to provide a stage name. While this is a super common practice for many who work in film, TV, and beyond, this doesn't appear to be the case for Ryan, who seemed to change her name due to its length. (After all, "Margaret" is rather long — and having to say five names in one doesn't exactly roll off the tongue.)
