Boateng has long been linked with a move to the Cottagers, with Goal exclusively revealing news of the transfer in mid-May.
And the Ghana international confirmed on Tuesday that he will begin training with the club immediately.
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"I believe it’s a good move and I’m finally happy to see this deal [confirmed]."
The 30-year-old will move to the Premier League on a free transfer following failed attempts both last summer and in January. The protracted saga saw Fulham enlist lawyers to investigate the legitimacy of his contract with Ukrainian club Dnipro, after Boateng's camp claimed his contract with the Ukraine club had been annulled.
Boateng has since been training with Greek side Olympiakos for the last few months while his contract dispute was taken to Fifa.
The holding midfield player will be joined by Venezuela international Fernando Amorebieta who has signed a pre-contract with the Londoners, while Goal also revealed last month that Fulham are also confident of wrapping up the signing of Roma goalkeeper Maarten Stekelenburg for £5.1 million.