Shane Warne raised one million Australian dollars (£ 528,514) for the Bushfire appeal after his "baggy green" Australian cap was sold at auction.
The legendary leg spinner, 50, wore the cap during his 145 test career, taking 708 gates with him.
The bush fire crisis in Australia has been going on since September and 27 people have died.
The cap was purchased from a Sydney bidder, with the highest bid being placed in the last minute of the auction.
Warne said he was "blown away" by the generosity and the final number "far above my expectations".
All of the money raised – the final price was AUD 1,007,500 – goes to the Australian Red Cross Disaster Relief and Recovery Fund.
Warne is Test Cricket's second most successful bowler. Only spinner Muttiah Muralitharan (800) from Sri Lanka has more gates.
The final price is more than double that of legendary Australian hitter Sir Donald Bradman, who was fetched in 2003 for AUD 425,000 (£ 225,000).
Baggy Green is an Australian player's test debut, and cricketers typically wear the same hat throughout their careers.
A variety of tennis stars, including Novak Djokovic, Rafael Nadal, Roger Federer and Serena Williams, have also pledged their support for the Bushfire appeal.