DIA (; Korean: 다이아; shortened from DIAMOND and backronym for Do It Amazing) is a South Korean girl group formed by MBK Entertainment. The group is currently composed of six members: Eunice, Jueun, Huihyeon, Yebin, Chaeyeon and Eunchae. DIA officially debuted on September 14, 2015, with their lead single "Somehow" from their debut album Do It Amazing.

Seunghee left the group in April 2016 after her contract expired and she would pursue her acting career. In May 2018, Eunjin decided to leave the group for health reasons. Jenny later left the group in July 2019, similarly for health reasons like Eunjin. In January 2022, Somyi departed the group after deciding to terminate her exclusive contract. In September 2022, all the remaining members departed from PocketDol following the expiration of their contracts and the group is currently on a hiatus due to the members focusing on their individual activities under different labels.