CANBERRA -- The Australian women have marked themselves as the team to beat in the 4x100 meter freestyle relay at the Tokyo Olympics.

Emma McKeon qualified fastest for the 100m freestyle at the Australian swimming trials in Adelaide on Wednesday night in 52.35 seconds, slower than the personal best of 52.19 she set in the heats.

"My focus now I have made it is on the Olympics," McKeon said after the race.

"The fact that I swam 52.1 this morning shows that I can swim fast in the morning which definitely gives me confidence for Tokyo."

She will be joined in the event by Cate Campbell, who will swim in her fourth Olympics in Tokyo after setting a time of 52.59.

"I dreamt of going to the Olympics when I was nine years old," Campbell said. "Most people get to do it once in their life and here I am, nearly 30, getting to do it for a fourth time. It's honestly a dream come true."

Six of the eight competitors in the final beat the qualifying time of 53.31, setting Australia up for a strong showing in the relay in Tokyo.

"Can we appreciate the depth of talent that we have in the women's 100m freestyle in this country? That is a world-class scoreboard," said Campbell, who was the star of the 2016 relay team.

Earlier on Wednesday night, Mitch Larkin qualified for the 200m individual medley in 1:56.29 while Jenna Strauch set a personal best time of 2:23.12 to qualify for the 200m breaststroke with Abbey Harkin.

The swimming trials will conclude on Thursday night with the men's 1500m and 50 freestyle, men's 100m butterfly and women's 800m and 50 freestyle and 200m backstroke.?