The American shaved almost two seconds off Mireia Belmonte’s previous record of 7:59.34, setting a new best time of 7:57.42.
Ledecky almost broke this record last week when she completed the 1500m in record time with a split time of 8:00.58, a second off world-record pace.
“I pushed myself a lot after last week,” Ledecky said, according to FINA’s, the sport’s world governing body, website.
“It’s great to have all these fans here to cheer us on. It’s nice to have some benchmarks (in short course).
And like her record-breaking 1500m swim, Ledecky led from the first turn, always ahead of world-record pace, and never seemed to be troubled by her fellow competitors.
Only Canada’s Summer McIntosh remained within touching distance of Ledecky, but she too dropped away from the American in the second half of the race and eventually finished in second, almost 10 seconds back.
“I was putting some pressure on myself after my swim in Toronto. I wish I had done it in Toronto. It’s always nice when you can hear a little bit of the crowd. It’s a fun way to start the fall and kick off the season,” Ledecky added.
“We usually don’t get the season started with an international level meet so it’s a little different for me.”