Jung Jae-sung (also spelled Chung Jae-sung; Korean: 정재성; Hanja: 鄭在成; Korean pronunciation: [tɕʌŋ.dʑɛ̝.sʌŋ]; 25 August 1982 – 9 March 2018) was a South Korean professional badminton player who specialized in men's doubles.
Together with his partner Lee Yong-dae, Jung spent forty weeks as World No. 1 in the men's doubles discipline between 2009 and 2012, winning eighteen BWF World Superseries tournaments and placing second at the BWF World Championships on two occasions in 2007 and 2009. He was a two-time winner of the All-England Open, gold medalist at the 2008 Badminton Asian Championships, and won the bronze medal at the 2012 Olympic Games in the final tournament of his professional career.