Theodore Agustin Gega (, born 18 August 1994), known professionally as Sin Boy, is a Greek rapper, singer, and songwriter of Albanian descent.
Gega was born on 18 August 1994 into an Albanian family in Nea Ionia, a northern suburb of Athens, Greece. Describing his early life, he stated that he was a victim of racism mostly because of his Albanian background.
In 2019, Gega began a romantic relationship with Kosovo-Albanian singer Rina. During an interview in Greece, he stated that he is not seeking Greek citizenship because of the mandatory military service.