Heo Sung-tae kicked off his acting career after joining the SBS talent show Miraculous Audition in 2011. In 2016, he came into prominence with his appearance in the period action-thriller film The Age of Shadows. In 2017, he played a supporting role in director Kang Yoon-sung’s The Outlaws, which earned him a Best New Actor for Film nomination at the 54th Baeksang Arts Awards. In 2018, he joined the cast of the SBS legal drama Your Honor, in which he was nominated for Best Supporting Actor at the SBS Drama Awards. In 2021, he starred in the mega hit Netflix survival drama Squid Game, which amassed a whopping 1.65 billion viewing hours on the first 28 days of its release. His performance in the series won him Best Actor at the 6th Asia Artist Awards.

Heo Sung-tae graduated from the Pusan National University with a degree in Russian language and culture. Prior to acting, he worked for LG Electronics and Daewoo Shipping and Marine Engineering Co.