The Better with You star took to Twitter to break the news, saying that she starts work on the medical drama today.
Garcia tweeted yesterday: "2morrow I have the honour of starting my work on @RoyalPains_USA! I'm a huge fan of show & xcited they asked me 2 hang out w them for a bit!"
She will be appearing in a recurring capacity as Dr Nina Greene, a doctor who it is hinted may be a former child star, reports TVLine.
Garcia is also known for her roles in Reba and Privileged.
Royal Pains is currently in its third season, with the remaining eight episodes airing in January 2012.
It was recently revealed that show star Mark Feuerstein will be directing an upcoming episode.
> JoAnna Garcia Swisher chats Better with You
Watch the trailer of the most recent Royal Pains episode below: