Kayqubad II (Old Anatolian Turkish: كیقباد; Persian: علاء الدين كيقباد بن كيخسرو, ʿAlāʾ ad-Dīn Kayqubād bin Kaykhusraw, c. 1238-1239 – 1254/1256) was the Seljuk Sultan of Rûm from 1249-1257.
He was the only son of the Seljuq Sultan of Rûm Kaykhusraw II and the Georgian princess Gurju Khatun (known as Tamar).
Kaykhusraw's elder sons, by different mothers, were Kaykaus II and Kilij Arslan IV, and also served as sultan after their father's death, often simultaneously.
In 1254 the Mongols asked that Kaykaus II, then nineteen years old, come in person to Möngke, the Great Khan.
He witnessed Bayju assembling his horsemen for the migration to Anatolia and sent messages advising his brothers to comply with the Mongol’s demands.