Do Ji-han began acting as a child, first appearing in the 2009 KBS2 series The Princess Has Returned. That same year, he became part of SBS’s Will It Snow for Christmas? In 2010, he played the young counterpart of Han Jae-seok’s character in the KBS1 sageuk Merchant Kim Man-deok. In 2012, he portrayed a rookie fireman in the disaster thriller film The Tower, which earned him a Best New Actor nomination at the 49th Baeksang Arts Awards. In 2013, he joined the cast of the SBS series Incarnation of Money. Also in 2013, he landed his first leading role in the tvN period drama Basketball. In 2016, he acted alongside Park Seo-joon, Go Ara, and Park Hyung-shik in the KBS2 fusion sageuk Hwarang. In 2017, he starred in the KBS1 daily series Lovers in Bloom.

Do Ji-han enlisted for his mandatory military service in December 2018.