Competing in the race in a short-course pool for the first time at the Toronto Pan Am Sports Centre, Ledecky clocked 15min 8.24sec to win the race by more than 40 seconds ahead of Brazil's Beatriz Dizotti.

Germany's Sarah Wellbrock set the previous record at 15:18.01 in 2019.

During the race, Ledecky also broke the American 800m short-course record with a time of 8:00.58.

After the race, she claimed that she had not targeted breaking the world record in Toronto, but said that she was "happy that hard work paid off".

"I didn’t have it as a set goal, I really didn’t know what to expect coming out of this meet, being my first meet of the season, taking most of August off, getting back into training rhythm, didn’t have any type of super preparation for this meet, just wanted to come in and race international swimmers being a meet in North American soil," she said.

Ledecky has also won silver medals in the 200m and 400m freestyle at the FINA Swimming World Cup so far.

She is the long-course 1500m world record-holder with a time of 15:20.48 set in 2018.

She is the Olympic champion in the event, and has also won six other gold medals at the Games.

The 25-year-old also won the women's 1500m freestyle race for the fourth time at the World Championships in Budapest earlier this year.

Those four triumphs are among her 22 medals won at the FINA World Championships, a women's record.