"The Best of Both Worlds" is a pop-rock song performed by American singer and actress Miley Cyrus for the Disney Channel television series Hannah Montana. Cyrus performs the song as Hannah Montana, who is the alter ego of the series' protagonist Miley Stewart. It was released as the debut and lead single from the Hannah Montana soundtrack album on March 18, 2006. "The Best of Both Worlds" is the theme song of the television series; in the series' third season, the 2009 Movie Mix is used as the theme. A live version is available on Hannah Montana & Miley Cyrus: Best of Both Worlds Concert (2008), a karaoke version is included in the soundtrack's karaoke series (2008), and the 2009 Movie Mix is featured on Hannah Montana: The Movie soundtrack (2009). The song has elements of bubblegum pop and pop rock. Lyrically, it is a showcase of the double life lived by Miley Stewart.

Hannah Montana is an American teen sitcom created by Michael Poryes, Rich Correll, and Barry O'Brien that aired on Disney Channel for four seasons between March 2006 and January 2011. The series centers on Miley Stewart, a teenage girl living a double life as famous pop singer Hannah Montana, an alter ego she adopted so she could maintain her anonymity and live a normal life as a typical teenager. Episodes deal with Miley's everyday struggles to cope with the social and personal issues of adolescence while maintaining the added complexities of her secret identity, which she sustains by wearing a blonde wig. Miley has strong relationships with her brother Jackson and father Robby Ray, as well as her best friends Lilly Truscott and Oliver Oken, who become aware of her secret. Overarching themes include a focus on family and friendships as well as the importance of music and discovering one's identity.