Margo Hayes is an American rock climber from Boulder, Colorado. On February 26, 2017, Hayes became the first woman to climb 5.15a when she sent Ramón Julián Puigblanque's La Rambla.
Hayes has also competed in all three events (lead, speed, and bouldering) of the International Federation of Sport Climbing. In the IFSC World Youth Championships in Guangzhou in 2016, she competed at the Juniors category, winning both the bouldering and lead events, placing 15th in speed, and placing first in the overall standings. In the same event in 2015 in Arco, Italy, Hayes won silver in bouldering and lead, behind Janja Garnbret, but in 2016 Garnbret was competing in a different category.