Thorpe, who has also earned 11 world titles and set 13 long-course world records, said he would remain involved in swimming in some capacity, The Age reported Tuesday.
"I'm actually going to discontinue my professional swimming career," he said. However, he said, "I intend to have a role with swimming still, I think that's important."
"I don't see myself competing again. I don't think it will happen. I won't rule it out but it's not going to happen," he told The Age.
"I realized I had to prove other things and let swimming take a back seat at this stage.
"I'm looking at a next phase, and that next phase means I am realigning the most important thing for me to do.
"Swimming falls somewhere short, which is never the way it used to be.''