Australia's triple Olympic gold medallist Kaylee McKeown set a women's 200m backstroke world record on Friday, firing a warning shot four months before the world championships.

McKeown clocked a blistering time of two minutes and 03.14 seconds at the NSW State Open Championships at Sydney Olympic Park.

The previous leading world mark was 2:03.35 set by Regan Smith of the United States at the 2019 world championships.

The 21-year-old McKeown also holds the 100m backstroke world record.

She has three Olympic gold medals, all from the Tokyo Olympics in 2021, in the 100m and 200m backstroke and the 4x100m medley.

She also claimed gold in the 200m backstroke at last year's world championships in Budapest.

The world championships this year are in Fukuoka, Japan, in July.