| Sir Khalifa bin Harub | |
| Succession: | Sultan of Zanzibar |
| Reign: | 9 December 1911 - 9 October 1960 |
| Predecessor: | Ali bin Hamud |
| Successor: | Sir Abdullah bin Khalifa |
| Birth Date: | 26 August 1879 |
| Birth Place: | Zanzibar |
| Death Place: | Zanzibar |
| Father: | Harub bin Thuwaini |
Sir Khalifa II bin Harub Al-Busaidi (26 August 1879 – 9 October 1960) (Arabic: السيد خليفة بن حارب البوسعيدي) was the ninth Sultan of Zanzibar from 9 December 1911 to 9 October 1960.
His father was Harub bin Thuwaini, a son of Thuwaini bin Said, Sultan of Muscat and Oman. 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 Sir Abdullah bin Khalifa.
Part of the museum of the Sultan's Palace in Zanzibar is dedicated to Sir Khalifa.