Playing his final victorious round on Father's Day, the 22-year-old from Northern Ireland dedicated his win to his dad.
Receiving the trophy, he called out to his father in the crowd: "Happy Father's Day - this one's for you."
As crowds chanted "Rory! Rory! Rory!" to the young champion, he added: "The whole week has been incredible. I could not have asked for any more and I am so happy to hold this trophy."
Rory's win yesterday was remarkable as only a few weeks ago he dramatically lost the US Masters on the final day. After three rounds McIlroy had had a commanding lead, but on the final day, as the world watched, he lost his nerve and his game disintegrated.
Although he said that he had put the failure behind him, his supporters were watching nervously as he once more stepped out on the final day as the tournament leader. They were desperately hoping history would not repeat itself.
But Rory delighted his fans and the young star played a dream final round to take the US Open 2011 title.
Ranked number four in the world, he now hopes he can mimic his childhood hero, Tiger Woods, and become the greatest player.
Meanwhile in Northern Ireland celebrations went on through the night. This is the country's second win in a row at the US Open. Last year fellow countryman Graeme McDowell took the title.
Rory said he was looking forward to getting home to celebrate with his friends and added: "For such a small nation to win two US Opens in a row is pretty special."
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