Swimmer Libby Trickett has hailed Australia's Olympic uniforms as "fantastic" although critics say they make the athletes look like lawn bowlers.

The opening ceremony uniforms unveiled in Sydney today feature green jackets with white slacks for men and white knee length skirts for women and white Dunlop volley shoes.

Trickett said she was excited that athletes were part of the design process and described the uniforms as iconically Australian, stylish and comfortable.

It's the first time the opening ceremony uniform has been unveiled ahead of the Olympic Games, which begin in London in July.