Tommy Caldwell is an American rock climber who has set records in sport climbing, traditional climbing, and in big-wall climbing. Caldwell made the first free ascents of several major routes on El Capitan in Yosemite National Park.

Big wall climbing is a form of rock climbing that takes place on long multi-pitch routes that normally require a full day, if not several days, to ascend. In addition, big wall routes are typically sustained and exposed, where the climbers remain suspended from the rock face, even sleeping hanging from the face, with limited options to sit down or escape unless they abseil back down the whole route. It is therefore a physically and mentally demanding form of climbing.