Ham Deok-ju (; born 13 January 1995), also known as Deok Ju Ham, is a South Korean professional baseball pitcher who is currently playing for the LG Twins of the KBO League.
He graduated from Wonju High School and was selected to Doosan Bears by a draft in 2013 (2nd draft, 5th round). In 2018, he changed back number from No.61 to No.1. He achieved his personal best of nine wins in 2017 season.
He represented South Korea at the 2018 Asian Games.