Uglûk was an Uruk-hai of Isengard. During the War of the Ring, Uglúk was the captain of the Orc band that captured Merry and Pippin at Amon Hen.

Uglúk was meant to lead the Orcs and Uruk-hai through Rohan to Saruman's fotress at Isengard, but the band was slaughtered by the Rohirrim. Uglúk was slain by Eomer, the Third Marshall of the Riddermark.