Jeong turned professional in April 2011.[6] In December 2011, he finished 16th in the PGA Tour of Australasia qualifying school, winning a place on tour for 2012.[7]
In 2012, Jeong played in all three stages of the European Tour qualifying school, obtaining a place in some Challenge Tour events for 2013. In early October 2013, he competed in the first stage of the qualifying schools for the European Tour (successfully) and the Web.com Tour (unsuccessfully).[8]
Jeong won his first championship as a professional on 20 October 2013, winning the ISPS Handa Perth International on the European Tour in a playoff over Ross Fisher. He was one of three players who had earned a place in that tournament from his position in the PGA Tour of Australasia's Tier 2 Money List for 2012, finishing 55th in the 2012 Order of Merit.[9] This win gave him an exemption on the European Tour until the end of 2015.