Inseong

Who Is Inseong?

Inseong, born Kim In-seong on July 12, 1993, is the main vocalist and oldest member of the South Korean boy group SF9, formed by FNC Entertainment. Known among fans as one of the sweetest voices in the group, Inseong has grown from a former SM Entertainment trainee into one of SF9’s most reliable singers and the group’s unofficial “big brother.”

Early Life and Trainee Days

Inseong grew up as an only child in Nowon-gu, Seoul, in a comfortable, well-educated household. Before landing at FNC, he actually trained under a different label, giving him a longer road to debut than several of his groupmates. He later enrolled at Kyung Hee University, studying journalism, since he once dreamed of becoming a broadcaster or a cartoonist. He even spent a year living and studying in London, which is why he’s the member most comfortable chatting with English-speaking fans and press.

Debut and Career With SF9

Inseong debuted with SF9 on October 5, 2016, through the single album “Feeling Sensation,” and has remained the group’s main vocalist across every era since, from the “Sensation” trilogy to more recent releases like “Fantasy” and “Love Race.” His clean, emotive tone anchors many of SF9’s ballad-leaning tracks and OST work. In 2022 he paused group promotions to complete his mandatory military service as part of an army band, returning to the stage in late 2023 alongside Youngbin. Building on that experience, he stepped into a solo lane in January 2026 with his first personal mini album, showing a more introspective, singer-songwriter side outside of SF9’s group concept.

Personality and Everyday Life

Friends and members describe Inseong as thoughtful, articulate, and a little bit of a foodie despite his slim frame. He enjoys quiet hobbies like painting, working through puzzles, and playing chess and piano, and he’s often the one members turn to for calm, well-reasoned advice. Off camera, he keeps a close bond with his family and has spoken warmly about how much he values the stability they gave him growing up.

Fun Fact

Inseong is frequently called the smartest member of SF9 by his groupmates, and he’s known for being unexpectedly skilled at writing short three-line poems, a lighthearted talent he’s shown off on variety shows over the years.