Radwańska began her summer hard-court season at the Rogers Cup in Toronto, Canada, where she defeated CoCo Vandeweghe and Tímea Babos before falling to Caroline Wozniacki in the third round. As the defending champion and top seed at the Connecticut Open she defeated Eugenie Bouchard and Peng Shuai before losing to Daria Gavrilova in her second semifinal of the season. This result saw her fall out of the top 10 for the first time since 2015. Following New Haven Open Radwańska entered US Open, where she was seeded 10th. She defeated Petra Martić and Yulia Putintseva in straight sets to advance to the third round. In the third round she lost a tight 3-hour/3 set match to CoCo Vandeweghe.