Radwan, ruler of Aleppo
Ridwan (c. 1077 – 10 December 1113) was a Seljuk emir of Aleppo from 1095 until his death.

Ridwan was born to the Seljuk prince Tutush, who had established a principality in Syria after his brother, Sultan Malik-Shah I granted him the region and its adjacent areas as an appanage. After the death of Malik-Shah, Tutush claimed the Seljuk crown, but he was killed by the forces of his nephew Berkyaruq near Ray, Iran. Following this, Ridwan moved to Aleppo and proclaimed himself the new emir. His brother Duqaq's declaration of a new emirate in Damascus split the Syrian Seljuk state in two and started a rivalry between the brothers which continued even after the arrival of the First Crusade in 1097. Ridwan tried to banish the Crusaders with gold, and fought the Principality of Antioch, a Crusader state established after the end of the Siege of Antioch in 1098. Bohemond I of Antioch invaded Ridwan's domain and reached Aleppo's surroundings. Bohemond's successor, Tancred, regent of Antioch, also warred against Ridwan, but the two later allied in a conflict against the emir of Mosul, Jawali Saqawa, supported by Baldwin II of Edessa and Joscelin I, the Lord of Turbessel.

Ridwan's personality was shrouded in mystery. He was surrounded by the Shia Arabs of Aleppo and favoured the Nizari Isma'ilis. Ridwan became a patron of the Assassins, giving them the freedom to practice and propagate their religion by letting them establish a "house of propaganda" in Aleppo and use the city as a base for future activities, which allowed the Assassins to establish a foothold in Syria. Ridwan had two of his brothers strangled to death, and had alleged ties to the assassination of several of his rivals, including the atabeg Janah ad-Dawla al-Husain. Ridwan's death in 1113 caused an anti-Isma'ili reaction within Aleppo. The administrative sovereignty of the atabeg Lu'lu' al-Yaya, and the effective elimination of the Assassins in Aleppo, characterized the reign of his successor, Alp Arslan al-Akhras. Seljuk rule in Aleppo soon ended in 1118 with the Artuqid takeover by Ilghazi.