In April 2016, FNC Entertainment launched the band's official comeback page along with the announcement of the fourth mini album Good Luck and the title track of the same name.

On May 16, the music video for the title track "Good Luck" were released online through YouTube and Naver's V App.

A first version of the music video was released, but was then quickly taken down allegedly because of the presence of an unwanted Toyota brand endorsement and of the visibility of a small part of Jimin's bosom.

In July 2016, Good Luck was reported to sell more than 41,000 copies in South Korea, marking it as AOA's fastest-selling album so far.

They concluded their promotional cycle for Good Luck with a final performance on SBS's Inkigayo on May 29, only two weeks after the release of the album.