Sayyid Sir Khalifa II bin Harub Al-Said GCB GCMG GBE (26 August 1879 – 9 October 1960) (Arabic: ????? ?? ???? ?????????) was the ninth Sultan of Zanzibar.
He ruled Zanzibar from 9 December 1911 to 9 October 1960.
In 1900, he married Sayyida Matuka bint Hamud Al-Busaid, daughter of the seventh Sultan of Zanzibar and sister of the eighth Sultan.
He was succeeded by his eldest surviving son, Sayyid Abdullah bin Khalifa.Part of the museum of the Sultan's Palace in Zanzibar is dedicated to Khalifa.