Alex Honnold is an American rock climber best known for his free solo ascents of big walls. Honnold rose to worldwide fame in June 2017 when he became the first person to free solo a route on El Capitan in Yosemite National Park, a climb described in The New York Times as "one of the great athletic feats of any kind, ever". Honnold also holds the record for the fastest ascent of the "Yosemite Triple Crown", an 18-hour, 50-minute link-up of Mount Watkins, The Nose, and the Regular Northwest Face of Half Dome. In 2015, he won a Piolet d'Or in alpine climbing with Tommy Caldwell for their completion of the enchainment of the Cerro Chaltén Group in Patagonia over 5 days.

Free solo climbing, or free soloing, is a form of rock climbing where the climbers climb solo without ropes or other protective equipment, using only their climbing shoes and their climbing chalk. Free soloing is the most dangerous form of climbing, and, unlike bouldering, free soloists climb above safe heights, where a fall can be fatal. Though many climbers have free soloed climbing grades they are very comfortable on, only a tiny group free solo regularly, and at grades closer to the limit of their abilities.