"Warrior" joined the Grand Fleet in December 1914 and was assigned to the 1st Cruiser Squadron under Rear-Admiral Sir Robert Keith Arbuthnot. At the Battle of Jutland on 31 May 1916, the 1st Cruiser Squadron was in front of the Grand Fleet, on the right side. At 5:47 p.m., the squadron flagship, , and "Warrior" spotted the German II Scouting Group and opened fire. Their shells felt short and the two ships turned to port in pursuit, cutting in front of the battlecruiser , which was forced to turn away to avoid a collision. Shortly afterwards they spotted the disabled German light cruiser and closed to engage. When the two ships reached a range of from "Wiesbaden" they were spotted in turn at 6:05 by the German battlecruiser and four battleships who were less than away. The fire from the German ships was heavy and "Defence" blew up at 6:20. "Warrior" was hit by at least fifteen and six shells, but was saved when the German ships switched their fire to the battleship when its steering jammed and caused "Warspite" to make two complete circles within sight of much of the High Seas Fleet.