Oleksiak was again part of the Canadian team in the 4×200 m freestyle relay, but despite breaking the Canadian record in the event final, the team finished in fourth place, one ordinal lower than their bronze medal performance in Rio. She next competed in the 100 m freestyle, where she had won gold four years prior. Qualifying through the heats and semifinals to the final round, she set a new personal best and national record with a 52.59 second final performance, finishing fourth behind bronze medalist Cate Campbell by 0.07 seconds. She described her turn as "frustrating", but "it's still fourth in the world so I'm not complaining." This was Oleksiak's highest placement in a major individual 100 m contest since her gold medal in Rio.