Pre-debut activities After moving back to South Korea, Ahn was scouted by
JYP Entertainment and became a trainee for three years, and lived in a dorm with members of the K-pop boy band
Got7. He eventually left the company due to stress as a trainee.
2015–2016: Beginnings with One O One and acting debut On October 1, 2015, Starhaus Entertainment launched the project group One O One, releasing their debut single "Love You". The group consisted of Ahn together with fellow Starhaus actors
Kwak Si-yang,
Song Won-seok and Kwon Do-kyun. However, the group presumably disbanded due to inactivity since January 2019. Ahn made his acting debut in the
MBC drama,
Splash Splash Love. He then became a cast member of the music variety show
Always Cantare. He had supporting roles in
One More Happy Ending,
Happy Home and
Entertainer in 2016.
2017–2020: Rising popularity His popularity rose after his first ever lead role in
Queen of the Ring in 2017. He then transitioned to lead roles thereafter. In 2018, Ahn starred in
Still 17, playing passionate high school student Yoo Chan – the captain of the high school rowing club. For his performance, he won Best New Actor Award and was nominated for the "Character of the Year" Award at the
2018 SBS Drama Awards alongside
Jo Hyun-sik and
Lee Do-hyun. In late 2019, Ahn became an MC at the 4th
Asia Artist Awards with
Leeteuk,
Lim Ji-yeon and
Nancy. In 2020, Ahn starred in the
second season of the hit
medical drama Dr. Romantic, playing general surgeon Seo Woo-jin with
Lee Sung-kyung as his leading lady. The show was a success, with both Ahn and Lee keeping their promise of singing for the fans as it crossed the double-digit mark for ratings. His performance in the drama earned him the
Best New Actor Award in television at the
56th Baeksang Arts Awards. For his portrayal of multiple roles as Ha Ram, Ilwolseong and Ma Wang, he received Excellence Award, Actor in a Miniseries Genre/Fantasy Drama and won Best Couple Award with Kim You-jung at
2021 SBS Drama Awards. He played the role of Kang Tae-mu, a third generation
chaebol and CEO. In March 2022, he was cast in the Netflix series
A Time Called You, South Korean adaptation of the Taiwanese drama
Someday or One Day. In May 2022, Ahn signed with The Present Company, the agency he co-founded with a manager who worked with him before his debut. In 2023, Ahn reprised his role as Seo Woo-jin in the
third season of the hit
medical drama Dr. Romantic. In 2024, he was cast in his first film, the live-action fantasy
Omniscient Reader: The Prophecy, an adaptation of the web novel ''
Omniscient Reader's Viewpoint'' by Sing Shong. Directed by
Kim Byung-woo, the film features Ahn as Kim Dok-ja, a character who finds himself in a world where a web novel he read has become reality. He partners with the novel's protagonist, Yoo Joong-hyuk (
Lee Min-ho), to alter their destiny and avert the world's destruction. In June 2025, Ahn made his voice acting debut as Jinu, a member of the fictional K-pop boy band Saja Boys, in the Netflix animated musical film
KPop Demon Hunters. The film quickly rose to the top of Netflix's global charts for three consecutive days, achieving the No. 1 ranking in 31 countries. This gave Ahn wider international recognition. ==Other ventures==