In her first event, McIntosh finished fourth in the women's 400m freestyle, breaking the Canadian national record with a time of 4:02.42. She advanced to the semifinals of the women's 200m freestyle, but placed ninth there and thus missed the final. She was chosen as part of the Canadian team for the 4 x 200 m relay, along with Oleksiak, Rebecca Smith and Kayla Sanchez. They set a new Canadian record in the event final, placing fourth. McIntosh's last event was the women's 800m freestyle, where she placed eleventh and thus did not advance to the final.