Sayyid Sir Khalifa II bin Harub Al-Said GCB GCMG GBE 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 also married his second wife sultana Nunu. 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.