Sebastian Rejman (born 13 January 1978) is a Finnish musician, actor and presenter, known as the singer-guitarist of the rock band The Giant Leap. He has composed and written the band's songs together with Petri Somer. After The Giant Leap went on a temporary hiatus, Sebastian formed a new band called Sebastian & The 4th Line Band. Rejman is from a bilingual working-class family in eastern Helsinki and lives in Kallio, Helsinki.