Mirror (stylised as MIRROR) is a Hong Kong Cantopop boy group formed through ViuTV's reality talent show Good Night Show - King Maker in 2018. The group consists of twelve members: Frankie Chan, Alton Wong, Lokman Yeung, Stanley Yau, Anson Kong, Jer Lau, Ian Chan, Anson Lo, Jeremy Lee, Edan Lui, Keung To, and Tiger Yau. They debuted on 3 November 2018 with the single "In a Second" (一秒間).

The group has won numerous accolades since their debut, including a Metro Radio Hits Music Award for Best Group, an Ultimate Song Chart Award for Group of the Year (Bronze), and Group of the Year (Gold) at the inaugural Chill Club Music Awards held by ViuTV. Mirror is considered one of the driving forces in the renewed interest of the Cantopop genre and to have prompted an unprecedented wave of fandom culture in Hong Kong. Their 2020 single "Ignited" won Top Ten Song of the Year at the Ultimate Song Chart Awards and the Chill Club Music Awards. Their 2021 single "Warrior" topped the Ultimate 903 Chart for two weeks, the first song from a group to do so in 15 years.

All members of Mirror have also debuted individually, most notably Keung To, who won the Ultimate Song Chart Award for My Favourite Male Singer, and Jer Lau, who won the Best Newcomer Gold Award. The members have also participated in various drama series, reality shows, and films, most notably Ossan's Love.