Diesel was born in Alameda County, California,[1] along with his twin brother, Paul.[3][4] His mother, Delora Sherleen (Sinclair) Vincent, is an astrologer.[5][6] Diesel has stated that he is "of ambiguous ethnicity".[7] His mother's background includes English, German, and Scottish.[8] He has never met his biological father, and has stated that "all I know from my mother is that I have connections to many different cultures".[9] Diesel has self-identified as "definitely a person of colour",[10] and has stated that his parents' relationship would have been illegal in some parts of the United States due to anti-miscegenation laws.[11] He was raised in New York City by his Caucasian mother and African-American stepfather, Irving H. Vincent, an acting instructor and theater manager.[4][10][12]
Diesel made his stage debut at age seven when he appeared in the children's play Dinosaur Door, written by Barbara Garson. The play was produced at Theater for the New City in New York's Greenwich Village. His involvement in the play came about when he, his brother, and some friends had broken into the Theater for the New City's space on Jane Street with the intent to vandalize it. They were confronted by the theater's artistic director, Crystal Field, who offered them roles in the upcoming show instead of calling the police.[13][14][15] Diesel remained involved with the theater throughout adolescence, going on to attend the city's Hunter College, where his creative writing studies led him to begin screenwriting. He has identified himself as a "multi-faceted" actor[16] as a result of early difficulties finding roles due to his mixed heritage.[16]