Küawiil Chan Küinich was the last Maya king of Dos Pilas. He is also known as the Ruler 4 and God K Sky Mahküina.
He reigned from 23 June 741 until c. 761. Dates of his birth and death are unknown.
It is likely that he was a son of the king Itzamnaaj Küawiil. He was a successor of Uchaüan Küin Büalam, who was likely his regent.
It appears that Küawiil Chan Küinich repaid his debt to his probable guardian and regent by recording his death and that of his wife on Hieroglyphic Bench 1. His accession followed the death of his predecessor within days, and it is possible that he was still young enough that the kingdom's enemies saw this as an opportunity to attack. The other possibility is that Küawill Chan Küinich set out to establish a military reputation for himself; even before his accession he had captured a lord from Ahkul and thereafter styled himself "Master of the Ahkul Lord", while Hieroglyphic Stairway 3 records captures from El Chorro, Yaxchilan and Motul de San José.
Yichüaak Büalam, king of Seibal, performed rituals overseen by Küawiil Chan Küinich.
A hieroglyphic stairway at Tamarindito records Küawiil Chan Küinich's "going out", a verb which often has the sense of "fleeing".
It is not known when and where did he died.