Her tour of Australia was postponed following the announcement.
A statement from Minogue's management said the 36-year-old's diagnosis was confirmed this week during a visit to the southern Australian city of Melbourne.
"Whilst at home in Melbourne with her family this week prior to her Australian Showgirl Tour, Kylie was diagnosed with early breast cancer," the statement said.
In the statement, Minogue said: "I was so looking forward to bringing the Showgirl tour to Australian audiences, and am sorry to have to disappoint my fans. Nevertheless, hopefully all will work out fine and I'll be back with you all again soon."
The Showgirl Tour was to have included performances in Sydney, Melbourne, Brisbane, Adelaide and Perth over the next month.