The Sharifian Caliphate (Arabic: الخلافة الشريفية, romanized: al-Khilāfat al-Sharīfiyya) was a caliphate proclaimed by the Sharifian leaders of the Hejaz in 1924, replacing the Ottoman Caliphate, which was abolished by the Grand National Assembly of Turkey. Even though the Banu Hashim held the caliphate at various points in history, Hussein bin Ali, the Sharif of Mecca, was the first and only caliph of the modern Sharifian (Hashemite) line.

In the Arab world, it represented the culmination of a long struggle to reclaim the caliphate from Ottoman hands. The first Arab revolts challenging the validity of the Ottoman caliphate and demanding that an Arab Sayyid be chosen as caliph can be traced back to 1883 when Sheikh Hamat-al-Din seized Sanaa and called for the caliphate as a Sayyid.

However, it was not until the end of the Ottoman caliphate, abolished by the Kemalists, that Hussein bin Ali was proclaimed caliph in March 1924. His stance towards the Ottoman caliphate was multifaceted; while he was hostile to it, he preferred to wait for its official abolition before assuming the title, so as not to break the Ummah by creating a second caliph alongside the Ottoman caliph. He also supported financially the late Ottoman dynasty in exile, to avoid them being ruined.

His caliphate was opposed by the British and French empires, Zionists, and Wahhabis, but he received support from majority of the Muslim population, as well as from the former Ottoman Sultan Mehmed VI. Although he lost the Hejaz and was exiled, then imprisoned by the British on Cyprus, Hussein continued to use the title until his death in 1931.

The Banu Hashim, from which the Hashemites originate, held the Sunni caliphate during various eras, most notably under the Abbasid caliphate.

The idea of the Sharifian Caliphate has been floating since at least the 15th century. The Sharifs of Mecca were significant figures in Sunni Islam because, in addition to them being Sharifs and their control over the two most important mosques in Islam, they also guaranteed the free passage for performing Hajj and defended the pilgrimage route against various raids carried out by Bedouins targeting the pilgrims.

Towards the end of the 19th century, a potential Sharifian Caliphate became more likely due to the decline of the Ottoman Empire, which had been heavily defeated in the Russo-Turkish War of 1877–1878. The initial Arab uprisings challenging the authority of the Ottoman caliphate and advocating for the appointment of an Arab Sharif as caliph can be traced back to 1883, when Sheikh Hamat-al-Din seized control of Sanaa and explicitly called for the establishment of a caliphate led by a Sharif. During this period, an increasing number of Muslim and Arab thinkers began to advocate for the idea of a caliphate returning to the Quraysh, such as Abd al-Rahman al-Kawakibi.

According to Israeli historian Joshua Teitelbaum, there is little evidence that the idea of a Sharifian Caliphate ever gained wide grassroots support in the Middle East or anywhere else for that matter. Saudi researcher Mai Yamani states that the idea "became extensively debated in the Arab world in the waning years of the Ottoman Empire."