Lonely is a song recorded by South Korean girl group Sistar.

[1] The song was a commercial success, peaking at number 1 on the Gaon Digital Chart.

[2] On May 2, 2017, it was announced by Starship Entertainment that Sistar would be making a comeback aiming for a June release.

"[7] Two more teaser images were released on May 25, followed by confirmation that the album would be promoted on music shows.

[9][10] Music show promotions for "Lonely" began on June 1, 2017, on Mnet M!