"Good Luck" is a song recorded by South Korean girl group AOA for their fourth extended play of the same name (2016).

The lyrics were written by Han Seong-ho, Jang Yeon-jeong and Innovators and the music was composed by Matthew Tishler, Aaron Benward and Felicia Barton.

On June 6, 2016 it was announced that the Japanese version of "Good Luck" would be released on August 3, 2016 as AOA's fifth physical single with no further details.

[5] On June 24, through the app Line, the group held a live broadcast, in which they discussed the upcoming release, revealing the prices among others details.

[6] On July 25, it was revealed that the Japanese version of "10 Seconds" and "Really Really" would be parts of the single, releasing audio teasers of both songs.

[7][8] On July 27, the pre-orders for the digital single started on iTunes Japan and "Good Luck" was available for pre-release download.

The first music video teaser was released on May 9, 2016 and was titled as "week version", showing the girls working as lifeguards on a beach.

[11] The second teaser was released a day later on May 10 and was titled as "weekend version" , showing the girls happy while walking on the street.

[17] The music video uses the same theme shown in the Korean version, with new close-up shots and outfit for each member and additional footage never seen before of the girls at the beach and in the club.

"[47][48][49] On May 27, 2016, AOA received the third trophy for first place for the song on Music Bank, winning against Twice's "Cheer Up", generating public doubt for the final score obtained.

Two days later, on May 29, producers from the show admitted the mistake, stating that the person in charge of calculating the scores made an error on the excel sheet, revealing that AOA took second place for the last week of May.