Kim Seul-gi made her acting debut with a minor role in the MBC series You’ve Fallen for Me. That same year, she joined Season 1 of the late-night television sketch comedy show Saturday Night Live Korea and left after four seasons. In 2014, she appeared in KBS2’s Discovery of Romance, which won her Best New Actress at the APAN Star Awards and the KBS Drama Awards. She also became part of the 2014 drama film Ode to My Father, which gave her the Best New Actress trophy at the 10th Max Movie Awards. In 2015, she acted alongside Park Bo-young and Jo Jung-seok in tvN’s Oh My Ghostess. She was then cast as the female lead in MBC’s time-slip fantasy drama special Splish Splash Love, opposite Yoon Doo-joon. In 2016, she played a supporting role in the SBS series Second to Last Love, which scored her an Excellence Award nomination at the SBS Drama Awards. In 2017 and 2019, she joined the main casts of Lookout and People With Flaws, which both aired on MBC. In 2020, she took home an Excellence Award at the MBC Drama Awards for her work in Find Me in Your Memory.

Kim Seul-gi attended the Seoul Institute of the Arts.