400 metres Individual Medley, Women

Canada’s Summer McIntosh was the heavy favorite for gold in the 400 IM. She had set the last two world records, most recently at the 2024 Canadian Olympic Trials, and was the 2023 World Champion. It was her first event of a busy schedule at the Paris Olympics.

Completely saving herself in the morning session, McIntosh qualified only third, behind the Americans Emma Weyant, the 2020 silver medalist, and Katie Grimes, who would also swim open-water at Paris 2024.

In the final, Grimes was somewhat close to McIntosh for about 150 metres, but then Summer was gone. She led at every turn, increasing her lead on each of the last four laps, and winning gold in 4:27.71, a full 5.69 seconds ahead of Grimes, the largest margin of victory in the event since Tracy Caulkins won by over nine seconds in 1984. Behind them, Weyant struggled home on the freestyle leg but held on for the bronze medal.

McIntosh would eventually end her Paris Olympics with four medals, three of them gold medals. She later won gold in the 200 IM and the 200 butterfly, adding a silver medal in the 400 freestyle. She also left Paris a few days shy of her 18th birthday, with anticipation of what might come in her career.