Nagasu began the 2017-2018 season at the 2017 CS U.S. International Figure Skating Classic, placing third in the short program and second in the free skate, and winning her the silver medal. She lands the triple Axel jump for the first time. She then competed in the 2017 Japan Open as part of Team North America and came in fourth in personal and third for team. For the Grand Prix series, she was assigned to compete at the 2017 Rostelecom Cup and the 2017 NHK Trophy. She finished ninth at the Rostelecom Cup, and fourth at the NHK Trophy.