"Lost in You" is a song by Canadian rock band Three Days Grace.

Written by the band's lead singer Adam Gontier, the song was released for radio airplay on February 1, 2011, as the fourth and final single from the band's third studio album Life Starts Now (2009).

The song expresses a more affectionate sentiment than is typically found in the band's music.

[2] While electric guitars still play a prominent role, the focus is on Adam Gontier's voice and the melody.

[2] On March 15, 2011, the band released an EP, via online download, containing the piano version of "World So Cold" and a cover of the Fleetwood Mac song "The Chain" in promotion of "Lost in You".