She won the Women's World Chess Championship 2015. In the first round, she drew with Yuanling Yuan in the classical games and then defeated her in the tiebreaks. In round two, she drew with Monika Socko in the classical games and defeated her in the tiebreaks. In round three, she defeated former Women's World Chess Champion Antoaneta Stefanova in the classical games by a score of 1½–½. In the quarter-final she defeated number one seed Humpy Koneru in the tiebreaks (2½–1½), and then beat Dronavalli Harika in the semi-final by tiebreaks (3½–2½). In the final she beat Natalia Pogonina with a score of 2½–1½. As a result of her victory, she obtained the Grandmaster title and qualified for the 2015 Chess World Cup which was held in Baku, Azerbaijan. In 2015, Muzychuk was awarded the Order of Merit, 3rd Class by Ukrainian President Petro Poroshenko.