Sung Dong-il began his acting career on stage before he was recruited to become a TV actor at the SBS open talent auditions in 1991. His early notable projects include the 1998 SBS drama Eun-shil and the 1999 KBS2 series Love in 3 Colors. In 2006, he joined the cast of the blockbuster romantic comedy 200 Pound Beauty, which jumpstarted his film career. In 2009, he appeared in director Kim Yong-hwa’s hit movie Take Off, which won him Best Supporting Actor at the 17th Chunsa Film Art Awards and the 7th Max Movie Awards. In 2010, he was once again named Best Supporting Actor, this time at the KBS Drama Awards for his portrayal of a slightly unhinged slave hunter in Chuno and a wily Japanese-Korean private investigator in Runaway: Plan B. In 2013 and 2014, he took home back-to-back Excellence Awards at the SBS Drama Awards for his work in the sageuk Jang Ok-jung, Live By Love and the medical series It’s Okay, It’s Love. In 2016, he scored a Best Actor nomination at the tvN10 Awards for his performance in the beloved Answer Me series. That same year, he received a Special Acting Award at the SBS Drama Awards for the fantasy romantic comedy Legend of the Blue Sea.

Sung Dong-il and his wife have three children together. He appeared with his son Sung Joon and daughter Sung Bin in the MBC family reality show Dad! Where Are We Going?