Nicholson an haife shi ne a ranar 22 ga Afrilu, 1937, a Neptune City, New Jersey, dan dan wasan kwaikwayo, Yuni Frances Nicholson (sunan wasan kwaikwayon Yuni Nilson). Mahaifiyar Nicholson ta kasance dan asalin Irish, Ingilishi, da kuma Jamus. Ta auri dan wasan Italiyanci na Amurka Donald Furcillo (sunan wasan kwaikwayon Donald Rose) a 1936, kafin ya fahimci cewa ya riga ya yi aure. Mawallafin Patrick McGilligan ya bayyana a cikin littafinsa Jack's Life cewa Eddie King (wanda aka haifa a Latvia) (wanda aka haifa Edgar A. Kirschfeld), mai kula da Yuni, na iya zama mahaifin mahaifin Nicholson, maimakon Furcillo.
yar wasan kwaikwayo