El-Hadji Malick Sy (Fulah: Allaaji Maalik Si, 1853–1922) was a Senegalese religious leader and teacher in the Tijaniyya Sufi Malikite and Ash'arite brotherhood.
Born in Gaya, northern Senegal, to a Fulani family, El-Hadji Malick Sy traveled to Mauritania, then to Saint-Louis, Senegal in 1884 as a religious student. He traveled to Mecca, then returned to teach at Louga and before establishing a zāwiya (religious center) at Tivaouane he settled permanently in 1898 in Tivaouane in 1902 following guidance received from his father in law Mor Massamba Diery Dieng father of his wife Sokhna Yacine Dieng and at the invitation of local leader Djibril Guèye, which became a center for Islamic education and culture under his leadership. In Senegal's Wolof country, especially the northern regions of Kajoor and Jolof, the Tijānī Order was spread primarily by El-Hajj Malick Sy.
After his death on 27 June 1922, Malick Sy was succeeded by his son Seydi Ababacar Sy as the khalife général des Tidjanes from 1922 to 1957. The family line has continued to hold the title, with El-Hadji Abdou Aziz Sy from 1957 to 1997, to the current khalife, Serigne Mabye Sy Mansour after his cousin El Hadji Abdul Aziz Sy Al Ibn who himself succeeded his brother Cheikh Ahmed Tidiane sy “Al Makhtoum”. The Gàmmu (Mawlid in Arabic, the celebration of the birth of Muḥammad) of Tivaouane gathers many followers each year. There is an Avenue Malik Sy in Dakar.
Malick is also the author of many poems and books about Islam, Muhammad, and At-Tijani: