Abū al-Qāsim Khalaf ibn al-‘Abbās al-Zahrāwī (936–1013), (Arabic: أبو القاسم خلف بن العباس الزهراوي‎‎), popularly known as Al-Zahrawi (الزهراوي), Latinised as Abulcasis (from Arabic Abū al-Qāsim), was an Arab Muslim physician and surgeon who lived in Al-Andalus.

He is considered the greatest medieval surgeon to have appeared from the Islamic World, and has been described as the father of surgery.

His greatest contribution to medicine is the Kitab al-Tasrif, a thirty-volume encyclopedia of medical practices.

His pioneering contributions to the field of surgical procedures and instruments had an enormous impact in the East and West well into the modern period, where some of his discoveries are still applied in medicine to this day.

Evacuation of superficial intracranial fluid in pediatric hydrocephalus was first described in detail in the tenth century by Abulkassim Al Zahrawi.