Bang Sung-joon (born July 10, 1990), credited mononymously as Sung Joon, is a South Korean actor and model. He became best known for his leading roles in the television series Flower Band (2012), Can We Get Married? (2012) and I Need Romance 3 (2014). He also appeared in the films Dangerously Excited (2012), Horror Stories 2 (2013), Pluto (2013) and The Villainess (2017). His recent works include starring in web series Island (2022-2023) and Call lt Love (2023) as well as in the television series The Fiery Priest 2 (2024).

Sung Joon began his entertainment career as a model, but soon switched to acting and debuted in the drama White Christmas in 2011. The same year he was cast in a supporting role in Lie to Me. In 2012, he was cast in a leading role in the teen drama Flower Band, where he played a free-spirited leader of a rock band.

Sung Joon made his film debut with Dangerously Excited.

In 2013, Sung Joon was cast in a lead role in the romantic comedy drama Can We Get Married? opposite Jung So-min. The same year, he starred in his first historical drama, Gu Family Book. Sung also starred in the horror film Horror Stories 2 and in the high school thriller Pluto.

In 2014, he was cast in the third installment of TvN's romantic comedy I Need Romance 3 in which he portrayed the character of a care-free songwriter. Later that year he took on the role of a plastic surgeon for the drama Discovery of Love.

In 2015, Sung Joon was cast as the lead in mystery melodrama High Society, playing a man who succeeds in spite of his poor family background. That same year, he also had a supporting role in Hyde Jekyll, Me, a romantic comedy where he played a hypnosis specialist.

In 2016, Sung Joon played the male lead in the romantic comedy drama Madame Antoine: The Love Therapist alongside Han Ye-seul.

In 2017, Sung Joon starred in the mystery comedy, Ms. Perfect alongside Ko So-young, playing a lawyer.