Passage: Downey an haife shi ne a Manhattan, New York, ƙarami na yara biyu. Mahaifinsa, Robert Downey Sr., ɗan wasan kwaikwayo ne kuma mai shirya fina-finai, yayin da mahaifiyarsa, Elsie Ann (née Ford), ta kasance 'yar fim ce wacce ta fito a cikin fina-finan Downey Sr. Mahaifin Downey rabin rabin Bayahude ne na Lithuania, kashi ɗaya cikin huɗu na Bayahude na Hungary, da kashi ɗaya cikin huɗu na Irish, yayin da mahaifiyar Downey ke da asalin Scottish, Jamusanci, da Switzerland. Sunan asalin dangin Robert shine Elias wanda mahaifinsa ya canza don shiga cikin Sojan. Downey da 'yar uwarsa Allyson sun girma a Greenwich Village. A matsayin yaro, Downey "magunguna ne suka kewaye shi".
Elsie Ann ta yi aure