The Dutchwoman eclipsed the previous record of 51.71 seconds set by Olympic champion Sarah Sjostrom at the 2017 World Championships.
"It still feels so weird ... I hope that it will sink in," the 26-year-old said after beating the world record.
"But it's always when someone goes faster, you see that it's going faster in the last (few) years. It's always when someone does it, more people start doing it, like it's a form of motivation."
"So I think more people will start swimming 52-lows, 51s, because it always goes like that, and I think that's really good for the sport."
Steenbergen finished seventh behind Sjostrom in the 100 metres final at the 2024 Paris Olympics, but has been setting the standards since the Swede went on maternity leave.
She bounced back from her Paris disappointment by defending her world title in Singapore last year, holding off Australia's former world champion Mollie O'Callaghan. She was also voted European Aquatics' best women’s swimmer of 2025 after retaining her title.
Steenbergen had signalled her intent earlier this year, clocking 51.86 seconds on the south coast of France at the Canet stop of the Mare Nostrum series in May.
"I really enjoy racing now, and I feel like I believe more in myself. Especially in the 100, I'm like, 'I know how to do it, I know what I want. Let's go,'" Steenbergen added.
It was the second world record Sjostrom has lost this month, with American Kate Douglass breaking the women's 50 metres freestyle world record at a U.S. Pro Swim Series event in Indianapolis.
The 24-year-old clocked 23.59 seconds to better the 23.61 set by Sjostrom at the 2023 world championships in Japan.
