Kaykhusraw III (Old Anatolian Turkish: كَیخُسرو سوم) or Ghiyāth ad-Dīn Kaykhusraw bin Qilij Arslān (Persian: غياث الدين كيخسرو بن قلج ارسلان; c. 1259-1263 – 1284) was between two and six years old when in 1265 he was named Seljuq Sultan of Rûm.
He was the son of Kilij Arslan IV, the weak representative of the Seljuq line who was controlled by the Pervane, Mu’in al-Din Suleyman.
Mu’in al-Din Suleyman, empowered by the Mongol khan Abagha, had Kilij Arslan IV executed in 1266.
The young Kaykhusraw became no more than a figurehead and played no part in the events of his reign, which were dominated first by the Pervane, the Mongol vizier of Rum and Fakhr al-Din Ali.
Kaykhusraw III was the last Seljuk sultan buried in the dynastic mausoleum at the Alaeddin Camii in Konya.