Shin Ha-kyun started out as a stage actor. In 1998, he landed his first onscreen project in the movie The Happenings. In 2000, he appeared in the mystery thriller Joint Security Area, which won Best Film at the 2000 Blue Dragon Film Awards and the 2001 Grand Bell Awards. The movie also earned him Best Supporting Actor trophies at the 8th Chunsa Film Art Awards and the 21st Blue Dragon Film Awards. In 2003, he was named Best Actor at the 4th Busan Film Critics Awards for his performance in the sci-fi comedy movie Save the Green Planet! In 2011, he headlined the KBS2 medical series Brain, in which he bagged the Daesang at the KBS Drama Awards. The drama also scored him a Best Actor for TV nomination at the 49th Baeksang Arts Awards. In 2018, he was recognized with a Top Excellence Award at the MBC Drama Awards for the crime-thriller Bad Detective, which was based on the British series Luther. In 2019, he took home the Best Actor honors at the 39th Korean Association of Film Critics Awards for Inseparable Bros. In 2021, he played an impulsive and eccentric sergeant in the JTBC series Beyond Evil, which was hailed Best Drama at the 57th Baeksang Arts Awards. He also received the Best Actor for TV trophy at the ceremony for his work in the series.

Shin Ha-kyun briefly dated actress Kim Go-eun, who was 17 years his junior. It was confirmed that they broke up in February 2017, eight months after they went public with their relationship. Former Brave Girls leader Eunyoung is his niece.