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Joshua Yong will also make his Olympic debut, having finished second in the 100m breaststroke final with a time of 59.48.

Yong dipped under Swimming Australia’s Olympic qualification time by just 0.01 of a second.

Williamson won the 50m breaststroke world title in Doha in February, but the 50m breaststroke is not an Olympic event.

He will make his Olympic debut in Paris in just over a month’s time.

“Sneaking under the minute is a pretty big achievement, so then to sneak under that 59 — there’s not a lot of guys around the world who have done that, so to be up in that calibre is really impressive and I’m just really happy with the work I’ve done,” Williamson told media poolside after his heat swim.

“It’s been a goal of mine [cracking the 59-second barrier]. It’s something I’ve been thinking about for a while and have been trying to execute.

Watch Australia’s Paris 2024 swimming trials on Nine and 9Now.

“I’m just happy I’ve done it and fingers crossed I can come back and swim a little bit quicker tonight.”

No other swimmer dipped under the minute barrier in the heats on Monday.

Joshua Yong qualified for the final with a time of 1:00.12, while Joshua Collett was the third-fastest qualifier with a time of 1:00.57.

Zac Stubblety-Cook, the reigning Olympic champion in the 200m breaststroke, got away slowly in his heat but charged home to win in 1:00.58.

According to the World Aquatics website, Williamson now ranks as the sixth-fastest 100m breaststroker in the world this year.

He said it felt surreal to have swum a time so close to the personal bests of Rickard and Sprenger.

“Springer and Rickard are both heroes of mine,” he said.

“I’ve idolised those guys from a very young age, so to be nudging their shoulders is pretty special.”