ABU DHABI, Jan 14, 2013 (AFP) - With the Abu Dhabi Grand Mosque lit up in the background, McIlroy stepped onto a stage wearing the Nike swoosh and revealed the clubs he will take into competition starting at this week's Abu Dhabi HSBC Championship in the UAE capital.
No exact details of what the deal was worth were released, but press reports have estimated it could bring the 23-year-old Northern Irishman up to $250 million (190 million euros) over 10 years.
"Growing up I always thought all the best athletes in most sports were Nike players and I'm looking forward to joining the Nike family," he said.
"I began testing the clubs late last year at the Nike factory in Texas and I could not be more happy.
"Hopefully now using Nike I have an even better year than last year. Last year was great winning a second major Championship and getting to No.1 in the world and this year I feel I can go to a new level and higher than I ever had and hopefully more majors."
McIlroy was introduced as a Nike staff player by Cindy Davis, president of Nike Golf, who indicated he had signed a 'multi-year' agreement.
"Today marks a significant moment for our brand and our golf business, and for the career of an extraordinary young athlete," she said.
"We could not be more thrilled with tonight's announcement.
"The beginning of 2013 for us is one of the most exciting times since Tiger Woods joined the 'Swoosh'."
McIlroy, who grew up in humble surrounds in suburban Belfast, insisted his switch of clubs from Titleist to Nike was not about the money.
"I don't play golf for the money as I am well past that," he said.
"I am Major Champion that I have always dreamed of being and I am World No. 1 as I have always dreamed of being, and really Nike is the company that can help me sustain that.
"So I play for Major titles, not the money."
Welcoming McIlroy to the Nike family were three of Nike's famed stars - Manchester United's Wayne Rooney, tennis great Roger Federer and 14-time Major winning Tiger Woods, who delivered video welcome messages to McIlroy.
McIlroy will face Woods in this week's Abu Dhabi HSBC Championship, part of the European PGA Tour with both players choosing the emirate to start their season's for the second straight year.
Like Woods, McIlroy was a boy wonder who was the world under-10 champion in 1998, turning professional in 2007, two months after finishing as the leading amateur in The Open at Carnoustie.
He had to wait until the 2009 Dubai Desert Classic for his first victory and oddly he has yet to win on European soil, all his successes since coming in the United States (five, including two majors), Asia (two) or back in the Middle East.
He finished last season with five birdies in a row to lift the DP World Tour title in Dubai.
It was the 2011 US Masters that put him on a new level in terms of fame and popularity.
McIlroy led by four with a round to play and was still out in front at the turn, but in an horrific back-nine meltdown he crashed to an 80 and ended up in only 15th place, 10 shots behind winner Charl Schwartzel.
The sporting world waited to see how long the mental scars would last, and got their answer two months later when he won the US Open by eight shots.
At just 22 he was the youngest winner of the title since Bobby Jones in 1923. A superstar was born.