Katie Ledecky and Sarah Sjostrom make a splash at swimming world championships

Australia tied their record gold haul at swimming's world championships with one day remaining, while greats Katie Ledecky and Sarah Sjostrom created more history on Saturday.

Australia claimed three more gold medals to take their count to 13 in Fukuoka, tying their best-ever tally from 2001 and 2005.

They secured their place on top of the medal table, meaning Australia will finish ahead of the United States for the first time since 2001.

Their night's work included a fifth world record this week for Australian swimmers and Kaylee McKeown completing an unprecedented backstroke world title sweep.

Cameron McEvoy, who claimed gold in the men's 50m freestyle, said his teammates' performances had spurred him on.

"It's hard not to tap into that and just go along with the flow," he said.

American Ledecky won the women's 800m freestyle to become the first swimmer ever to win the same event six times at a world championships.

Sarah Sjoestroem won the women's 50m butterfly final. Getty

Sweden's Sjostrom won her fifth in the 50m butterfly, then promptly dived back into the pool 20 minutes later and broke her own world record in the 50m freestyle.

There was also gold for France's Maxime Grousset in the men's 100m butterfly.

Australia's mixed 4x100m freestyle relay team claimed the final title of the day in a world record time of 3min, 18.83sec, giving Mollie O'Callaghan her fifth gold medal of the week.

"I've had a lot going on this week and I think I've just got to maintain and be as professional as possible," said O'Callaghan, who has been part of four team or individual world records this week.

"Just sticking around with the team and keeping it quite closed has really helped me."

Ledecky claimed her 16th individual world