At the 2021 World Championships, Uno placed sixth in the short program after a fall on his triple Axel. In the free skate, he two-footed his quadruple Salchow and put a hand down for his quadruple toe loop but still managed to place third in the free skate and fourth overall, behind Nathan Chen and compatriots Hanyu and Kagiyama. Uno was subsequently announced as part of the Japanese team for the 2021 World Team Trophy. He placed ninth in the short program and sixth in the free program, with Team Japan placing third overall at the competition.