Found a Jamaican grill and lounge bar in Busan called Yaman Joint. I had never previously had Jamaican food before, so I can’t really comment on authenticity, but they’ve got a cool laid-back ambiance.
The food ranges in price from 8,000₩ to 15,000₩. There are sets which include the house salad, pasta with Alfredo sauce, fish tacos, and jerk chicken. In my opinion, the best thing is the jerk chicken.