Jeon Hyo-sung was a finalist on Mnet’s singing audition show Battle Shinhwa in 2005. She then became part of the line-up for the South Korean girl group Five Girls, but they disbanded even before they officially debuted in 2007 due to their agency’s financial problems. In 2009, she finally debuted with the South Korean girl group Secret with the single I Want You Back. In 2010, they released their first mini album titled Secret Time, which produced their breakthrough song Magic. In 2014, she released her solo debut album Top Secret, which peaked at number 2 on the Gaon Weekly Album Chart.
Jeon Hyo-sung made her acting debut in the 2013 OCN drama Ghost-Seeing Detective Cheo-yong. That same year, she starred in the KBS1 daily series My Dear Cat, which earned her a Best New Actress nomination at the 7th Korea Drama Awards. In 2016, she joined the SBS crime thriller Wanted, which won her a Special Award at the SBS Drama Awards. In 2020, she played a supporting role in the tvN series Memorist.
Jeon Hyo-sung majored in theater and film at Inha University. In December 2012, she and her fellow Secret members were involved in a car accident, where she sustained a knee injury.