Carolina Marín
In May, Okuhara helped Japan to win the Uber Cup again after 37 years. Japan beat Thailand by 3–0 in the final. Okuhara didn't lose any of her match in Uber cup. She went to World Championships in Nanjing as defending champion but lost to the player she beat in 2017 final P. V. Sindhu in 2 straight games in quarterfinals. She won her first ever World Tour Title; the Thailand Open Super 500 by defeating P. V. Sindhu 21–15 and 18. In addition, she reached five more finals and won 2 of them in Korea and Hong Kong, both Super 500 events. Her final finishes were in Japan Super 750 (lost to Carolina Marín) Fuzhou Super 750 events (lost to Chen Yufei) and World Tour Finals in Guangzhou to P. V. Sindhu.