The year he turned 18, he joined the Hyundai Unicorns through the second phase of the rookie draft. In 2007 he made his first-team debut and became the regular shortstop in the second half. In 2008 the Hyundai Unicorns were dissolved and he became a member of the Woori Heroes. In 2009 he moved to third base and hit .284 with 18 home runs, 63 RBIs and 30 stolen bases. In July 2010 he was traded from Nexen to Lotte.
The breakthrough yearThe year he turned 27, in the Incheon Asian Games final against Taiwan in September, he hit a two-run single in the eighth that sealed the win, and his name became widely known. The gold medal earned him a military service exemption. That December he finished second to Park Sok-min in Golden Glove voting at third base.
In 2015 he helped win the first Premier12 and was named to the best nine, but his December posting bid for the major leagues drew no offers. In 2016 he hit .335 with 27 home runs and 113 RBIs. In January 2017 he signed with the San Francisco Giants, and in June he homered in his debut game, a first for a Korean major leaguer. In December he signed with the KT Wiz as a free agent for four years and 8.8 billion won.
In 2018 he won his second Asian Games gold, at the Jakarta-Palembang Games. In 2019 he hit 20 home runs. In 2020 he won his first Golden Glove at third base.
In June 2021 he was named to the Tokyo Olympics team, and in November, as captain, he led KT to its first combined regular-season and Korean Series title.
In September 2022 he hit his 200th career home run to reach 200 home runs and 200 stolen bases, and in December he married T-ara member and actress Jiyeon. In 2023 he reached the Korean Series but lost to the LG Twins and finished as runner-up.
In November 2024 his divorce mediation with Jiyeon was finalized. In December 2025 he officially announced his retirement. In February 2026 he signed with SM C&C and began television work. In September he held his retirement ceremony and attended the press conference for Disney+ Deadly Tag, his first regular variety show since retiring.
Jae-gyun Hwang (born Jul 28, 1987) made his first-team debut with the Hyundai Unicorns on Apr 21, 2007, the year he turned 20, and became known after the Incheon Asian Games final on Sep 28, 2014, the year he turned 27. He announced his retirement in 2025, the year he turned 38, and now works as a TV personality.
Ages are by calendar year (the year minus the birth year), birthdays aside.