Sinjin Rosa was born in Manhattan, New York to, Dixie Garrastegui and Oscar Rosa. At the age of 7, Sinjin's mother passed away. He then moved in with his father in the Bronx where he was raised. While growing up, Sinjin was heavily into sports but always felt like an "actor". At 10 years old while watching a movie he said to himself "This is what I want to do". Sinjin immediately joined school theatre, starring in multiple plays and musicals. After graduating high-school he went to college in Florida. He graduated with a Bachelors degree and then moved to Los Angeles. He has gone on to star in films such as Circus Kane, Second Chance and as of most recently is a series regular on the upcoming TV show Fraxtur.