Shin Jae-ha made his acting debut in the 2014 film Futureless Things, in which he had a kissing scene with singer-actor Gong Myung. That same year, he played the younger counterpart of Yoon Kyun-sang’s character in the SBS series Pinocchio. In 2016, he starred alongside Kim So-hyun and Ji-soo in the three-episode KBS2 drama special Page Turner. In 2017, he was paired with Ryu Hwa-young in the web series Trace of the Hand, which won him Best Actor at that year’s Seoul WebFest Awards. In 2019, he joined the main cast of the SBS mystery drama VIP, which scored him a Best New Actor nomination at the SBS Drama Awards. In 2020, he was cast as one of the main characters in tvN’s My Unfamiliar Family, which was nominated for Best Drama at the 57th Baeksang Arts Awards.

Shin Jae-ha attended Dankook University. He enlisted for his mandatory military service in November 2020.