Business tycoon JP McManus has donated €100,000 to every GAA county board in Ireland to distribute among clubs.
The multi-millionaire from Limerick gave a total of €3.2m in what a GAA spokesman called an "incredible gesture".
Mr McManus has been the main sponsor of Limerick GAA for many years through the Sporting Limerick brand and revelled in the hurlers' first All-Ireland win in 45 years last month.
He sent a letter to each board outlining that the money is for the development of GAA across the country.
Speaking to the Herald, a spokesman for the GAA said the donation had come as a huge surprise.
"It is an incredibly generous gesture from a man who has been an incredible supporter of Limerick GAA," he said.
"It will be very, very well received by hundreds of clubs who are trying to nourish young talent."
Former GAA president Sean Kelly praised Mr McManus for his generosity.
"This is a gesture of extraordinary generosity from JP, who has always been a huge supporter of our games," he said.
"The donation of €3.2m, to be divided among the 32 counties, shows how much JP cares about the GAA and how much he wants to see it continue to grow and develop.
"As a former GAA president, and indeed county chairperson, I know how beneficial this will be to county boards.
"We have just come to the end of a wonderful GAA Championship which saw great wins for Dublin, Cork, and of course JP's native Limerick - some of the most impressive performances we have ever seen.
"This additional funding will help counties to invest in the development of the games, improve their facilities, and bring their teams to the next levels."
Horse racing magnate Mr McManus celebrated with the players in the Limerick dressing room after their All-Ireland win over Galway.
He said after the win he wanted to make sure he wasn't dreaming.