In June Millousi competed at the 2018 Mediterranean Games where she helped the Greek team place seventh and individually she placed fifth in the balance beam final. In August she competed at the European Championships. She qualified to the balance beam final and finished in eighth place. In October Millousi competed at the World Championships. During qualifications she placed 32nd on balance beam and did not qualify to the event finals. She announced her retirement shortly after, officially retiring on October 30, 2018.