Huntelaar, who has become surplus to requirements at Real following the Spanish club's massive spending spree, will join Milan on a four-year contract, the Serie A club said on Thursday.
"The Dutch footballer will undergo medical checks tomorrow after which he will sign a contract that will bind him to the club until June 30, 2013," read a statement on the club website.
Huntelaar, who turns 26 next week, will be Milan's first major investment so far in the close season.
The announcement comes a day after Milan owner Silvio Berlusconi said funds would be found for a "great goalscorer" and that Chelsea target Andrea Pirlo was staying.
Until now, Milan's only significant reinforcements were American defender Oguchi Onyewu, a free signing from Standard Liege, and Brazilian Thiago Silva.
NEWS: Milan set to seal Huntelaar deal
NEWS: Huntelaar on verge of Milan move
NEWS: Harry still interested in Huntelaar
NEWS: Leonardo confirms Huntelaar interest
NEWS: Real pay-off may help hurry Huntelaar move
NEWS: Italians mull Huntelaar moveNEWS: Redknapp - Huntelaar wages beyond us
NEWS: Redknapp - I am in hunt for Huntelaar
NEWS: Huntelaar switch to Stuttgart collapses
NEWS: Stuttgart set to seal Huntelaar deal
NEWS: Real deny Arsenal approach for Huntelaar
NEWS: New bidders enter Huntelaar hunt
NEWS: Pardeza: Huntelaar sale close to conclusion
