Fantastic Duo is a South Korean TV program produced by SBS. Its concept is unique: everyday people (non-professional singers) get the chance to sing a duet with top-tier Korean artists through a special video call application. The show uses a "All-Star" judge system where the audience votes live. It is known for emotional performances, viral-worthy duets, and showcasing hidden musical gems among the public.

Seasons ran from 2016 to 2017 (Season 1 and 2), with a brief revival in 2020 (Season 3, sometimes called Fantastic Duo: Backstage ). "Vietsub" refers to Vietnamese subtitles . Since Fantastic Duo is a Korean show without official Vietnamese dubbing or subtitles on most global platforms, Vietnamese fan communities take on the task of translating, timing, and embedding Vietnamese subtitles into the episodes.