Her maternal grandparents were King Fuad I and Queen Nazli of Egypt; and her paternal grandparents were Rezā Shāh Pahlavi and Queen Tadj ol-Molouk of Iran. She is also the niece of King Farouk I of Egypt - and thus cousin of the last Egyptian king, Fuad II. Therefore, her ancestry includes Circassian, Persian, French, Albanian, and Azerbaijani. Shahnaz Pahlavi was educated in Switzerland.
Her first marriage was to Ardeshir Zahedi on 11 October 1957, one time Iranian foreign minister and twice Iranian ambassador to the United States (1957–1964 and 1972–1979). She was seventeen when she got married at Golestan Palace in Tehran. Zahedi and she first met in Germany in 1955. The couple have one daughter, Princess (styled "Vala Gohari") Zahra Mahnaz Zahedi (born 2 December 1958 in Tehran). They divorced in 1964.
Shahnaz later married Khosrow Jahanbani in February 1971 at the Iranian Embassy, Paris.[8] They have one son, Keykhosrow (born 1971) and one daughter, Fawzia (born 1973).
During her father's reign, Shahnaz had investments in agricultural enterprises and assembly plants of Honda bicycles and motorcycles.