Alp-Arslan, Turkish Alparslan ("Courageous Lion"), original name ʿaḍud al-Dawla Abū Shujaʿ Muḥammad ibn Dāʾūd Chaghribeg, (born c. 1030—died November 1072/January 1073), second sultan of the Seljuq Turks (1063–72), who inherited the Seljuq territories of Khorāsān and western Iran and went on to conquer Georgia, Armenia, and much of Asia Minor (won from the Byzantines).

Alp-Arslan was the son of Chaghri Beg, the ruler of Khorāsān in Iran, and the nephew of Toghrïl, the governor of western Iran, the base of Seljuq expansion. In 1061 his father died. When, in 1063, his uncle died without issue, Alp-Arslan became sole heir to all the possessions of the dynasty except Kerman, in southern Iran, which was held by one of his brothers, whom he promptly reduced to vassalage.He likewise easily eliminated the son of one of Toghrïl's widows, as well as Qutlumush, a cousin and rival.