Jang Nara debuted as a singer in 2001 with the album First Story, but it was her second album titled Jjang Nara Vol. 2–Sweet Dream that launched her into prominence in 2002. The album produced the hit song Sweet Dream, which won the Daesangs at the 2002 KBS and MBC Music Awards and the Bonsangs at the 2002 Golden Disk and Seoul Music Awards. That same year, Jang Nara landed her first leading role in the SBS romantic comedy series Successful Story of a Bright Girl. Her performance in the drama earned her the Best New Actress trophy at the 39th Baeksang Arts Awards. In 2005, she released her first Chinese album, which was a huge success. Also in 2005, she headlined her first mainstream Chinese series My Bratty Princess, which catapulted her as a Hallyu star in China. In 2014, she reunited with her Successful Story of a Bright Girl co-star Jang Hyuk in Fated to Love You, which is a remake of the Taiwanese drama of the same name. She won a Top Excellence Award at the 2014 MBC Drama Awards for her performance in the series. In 2018, Jang Nara starred in the hit SBS drama An Empress’s Dignity, in which she received a Top Excellence Award at the SBS Drama Awards.

Jang Nara revealed in an interview that her hectic workload as a celebrity resulted in several health issues such as gastric ulcers, panic disorder, and bulimia, among others. In 2014, she also halted her singing activities due to stage phobia. Her father Joo Ho-sung is a theater actor, producer, and director. He also manages her career. Her older brother Jang Sung-won is also an actor. Their family owns the talent management agency Rawon Culture. In June 2022, Jang Nara married a non-celebrity.