Johann was born in Tallinn as the son of a musician Tarmo Urb. At the age of ten Johann moved to live in Finland with his mother and her new Finnish husband. Mostly they stayed in Tampere. When Johann turned 17, he moved to the United States where his father lived as he started his career in modeling in New York, which led him later on to pursuing a career in acting. He studied in the Lee Strasberg Theatre and Film Institute.
In 2001, Urb landed a small part in the film Zoolander. Later, he made an appearance in the short film Fear of Feathers and had a role in one episode of CSI: Miami. In 2004, Urb appeared in the short-running television series The Mountain. Following that, he guest starred in several television shows and made smaller film roles.