[3][4][5][6] She starred in the English language film Mona Lisa and the Blood Moon in 2021 and in the Netflix series Money Heist: Korea – Joint Economic Area in 2022.

[2] Jeon Jong-seo started her acting career after she joined a management agency and went on her first audition in August 2017, for director Lee Chang-dong's mystery flick Burning.

[15] Pierce Conran of Screen Anarchy wrote, "Plucked from auditions, first-timer Jeon Jong-seo achieves something almost unthinkable for a rookie, as she embodies a character who is caught between her dreams and reality, her yearning for freedom and role in society, and the powerful desires of those around her and her own.

"[16] John Powers of Vogue wrote, "[i]n a marvelous screen debut, she gives a radiant turn, blooming so brightly—especially in a stoned twilight dance to Miles Davis—that she often outshines her male costars.

"[17] Justin Chang of Los Angeles Times wrote, "Jeon, making a remarkable screen debut, brings this young woman to beautiful, soulful and defiant life.

"[23] James Marsh of South China Morning Post wrote, "Jun cements her position as Korean cinema's unhinged ingénue du jour, following her star-making turn in Lee Chang-dong's Burning, with a brilliantly psychotic performance that reveals Young-sook to be just as dangerous as she is fragile and damaged.

"[24] Decider's Jade Budowski wrote, "Jong-seo Jun is magnificent as Young-sook [...] She's convincing in both her quieter moments and her more maniacal outbursts, masterfully drawing out all the thrills and chills you could hope for with a movie of this nature".

[33][34] Jeon's performance, as a woman with unusual powers who escapes from a mental asylum and tries to make it on her own in New Orleans, received positive reviews.

Lovia Gyarkye from The Hollywood Reporter wrote, "Jeon (Burning) excels in her first English-language role, imbuing Mona with personality despite her limited dialogue".

[36] She next played a late 20s single woman who swears off relationships in a romantic comedy film Nothing Serious alongside Son Suk-ku, directed by Jeong Ga-young of Hit the Night.