The 2008 K2 disaster occurred on 1 August 2008, when 11 mountaineers from international expeditions died on K2, the second-highest mountain on Earth. Three others were seriously injured. The series of deaths, over the course of the Friday ascent and Saturday descent, was the worst single accident in the history of K2 mountaineering. Some of the specific details remain uncertain, with different plausible scenarios having been given about different climbers' timing and actions, when reported later via survivors' eyewitness accounts or via radio communications of climbers who died (sometimes minutes) later in the course of events on K2 that day.

The main problem was reported as an ice avalanche occurring at an area known as "the Bottleneck", which destroyed many of the climbers' rope lines. However, two climbers died on the way up to the top prior to the avalanche. Among the dead were people from France, Ireland, Korea, Nepal, Norway, Pakistan, and Serbia.