Three-time Olympic champion Libby Trickett has announced her retirement from swimming with immediate effect.

The 24-year-old won six medals over two Olympics in Beijing and Athens as well as eight gold, three silver and four bronze medals from four World Championships.

The Australian's final competitive appearance saw her set a new short-course world record in the 100 metres freestyle in August.

Trickett made her mind up to retire after this year's World Championships in Rome where she won a silver and two bronze medals. She will now concentrate on pursuing a career in the media.