"I'll Be Back" () is a Korean song by South Korean boy band 2PM. It was released on October 11, 2010 via JYP Entertainment as the lead single for ', the group's first EP. "I'll Be Back" has won 2PM several accolades, including the 2010 MAMA Award for Best Male Group and the 2010 MAMA Award for Best Dance Performance.
"I'll Be Back" is a dance-pop song composed and written by Park Jin-young. The song runs 3 minutes and 34 seconds in length. The lyrics of the song are from the perspective of a man in denial over a breakup, claiming his ex-partner will return to him.
On October 9, 2010, a teaser for the music video of "I'll Be Back" was released on 2PM's official website and YouTube channel. On October 11, the music video for "I'll Be Back" was released.
The track would later be included in 2PM's second studio album, Hands Up, released on June 20, 2011. A Japanese version of the song was included as the B-side track of 2PM's third Japanese single, "Ultra Lover", released on November 2, 2011.
The music video is heavily inspired by the Terminator series of films, as the title of the song is the same as the films' famous catchphrase "I'll be back", and the choreography of the song begins with member Jun. K recreating the T-800 Terminator's death scene in ' by raising a thumbs-up above his head while singing the catchphrase.
The music video features the members dressed in metallic eye shadow and leather post-apocalyptic fashion, dancing in brightly lit rooms. The choreography of the song heavily focuses on the running man, and the ending of the music video includes a dance break sequence which incorporates acrobatic flips and breakdancing, hallmarks of 2PM's early signature style, to the beat of mechanical sound effects.