The World of Warcraft expansion that raised the level cap from 100 to 110 was Legion.
Legion, the game’s sixth expansion, launched on August 30, 2016, after Warlords of Draenor had capped characters at level 100. Its new level cap was 110, with most of the adventure taking place across the Broken Isles as Azeroth’s heroes fought the Burning Legion.
The increase was accompanied by major class-focused systems. Legion introduced artifact weapons tied to class specializations, Order Halls where class members coordinated their campaigns, and the Demon Hunter hero class. Demon Hunters began at level 98 and were initially limited to Night Elves and Blood Elves.
Players sometimes confuse Legion’s level increase with Battle for Azeroth, which raised the cap again from 110 to 120. Shadowlands then dramatically reversed the numerical scale through the first level squish, reducing the 120 cap to 60. Legion therefore marks the specific transition from 100 to 110, not just a general period of level expansion.