Ji-yeon began her entertainment career appearing in several advertisements and music videos. In May 2009, she released the digital single Women’s Celebration in collaboration with Davichi and SeeYa. Two months later, she debuted as a member of T-ara with the single Lie. In December 2009, they released their debut studio album titled Absolute First Album. In 2012, the group was hit with internal discord issues, resulting in a dip in their popularity. They started focusing their promotional activities in China and went on to become one of the most popular K-Pop girl groups in the said country. In May 2014, Ji-yeon made her solo debut with the release of the extended play Never Ever.

Ji-yeon kicked off her acting career with cameo appearances in KBS2’s Hello! Miss and SBS’s Lobbyist in 2007. She then landed a supporting role in the 2008 SBS daily series Ae-ja and Min-ja. In 2009, she acted alongside Lee Seo-jin and Im Joo-eun in MBC’s Soul. In 2010, she starred in the KBS2 dramas God of Study and Jungle Fish 2. Her work in the former earned her a Best New Actress nomination at the 2010 KBS Drama Awards. That same year, she became part of the horror film Death Bell 2: Bloody Camp. In 2012, she joined the main cast of KBS2’s Dream High 2. In 2019, she played a violinist in the KBS2 drama Let Me Hear Your Song. In 2021, she appeared in Imitation, which also aired on KBS2.

In February 2022, Ji-yeon announced her marriage to professional baseball player Hwang Jae-kyun.