2015–present: Rise in popularity
In 2015, the relative newcomer drew mainstream notice when she joined the fourth season of the Korean reality show We Got Married, where she was paired with singer-actor Lee Jong-hyun.
Gong started to gain attention as an actress with her role in the historical drama Six Flying Dragons (2015–2016). She won the New Star Award at the SBS Drama Awards. Gong was also casts in the revenge series The Master of Revenge. She was then cast in her first leading role in youth sageuk My Only Love Song, which co-stars her We Got Married partner Lee Jong-hyun. The drama premiered on Netflix in 2017. In 2017, Gong starred in tvN's romantic comedy Introverted Boss. The same year, she took on a lead role in science fiction mystery series Circle.
It was announced that Gong signed with BH Entertainment in March 2018, after her contract with Yuko Company expired and both her and the company decided not to renew. In 2018, she starred in KBS' science fiction romance drama Are You Human? with Seo Kang-joon. She also starred in the short film My Dream Class, and sang the theme song for the movie. In 2019, Gong was cast in the historical romance drama Flower Crew: Joseon Marriage Agency.
On July 13, 2020, Gong signed with a new agency, Varo Entertainment. It was also announced that Gong has been cast in the upcoming film Handsome Guys alongside Lee Hee-joon. In March 2021, Gong was confirmed to be starring in tvN's fantasy drama Bulgasal: Immortal Souls which aired in December 2021. Gong was recognised for her work in the film Aloners where she has won multiple awards, including the "Best New Actress" award at the 42nd Blue Dragon Film Awards.
In 2022, Gong was cast in the SBS drama The First Responders alongside Kim Rae-won and Son Ho-jun. The second season premiered in 2023.
In 2025, Gong starred in Netflix's crime thriller television series Karma directed by Lee Il-hyung. It is based on the Kakao webtoon of the same name by Choi Hee-seon, about people who are unexpectedly entangled and destroy each other while pursuing their own desires.
Gong starred as Queen Dowager Yoon Yi-rang in the television series Perfect Crown in 2026. She was praised for her performance and interpretation of her character. Maeil Business Newspaper deemed Gong a standout, while OSEN's Ha Su-jeong wrote that she "exuded charisma as the Queen Dowager". Pop culture critic Ha Jae-geun commented to Ilgan Sports that Gong "held the center [of the series] well with her very serious and weighty acting," adding that "she has been an actress who has shown great acting skills, but she is shining even brighter in this work".
