The 54-year-old Frenchman, who succeeded Lennart Johansson as president in 2007, is expected to be unopposed when the decision is made at the next UEFA Congress in May 2011.
Platini told delegates in a simple statement: "I have been asked about my future by the press and other people but wanted to tell you first that I am happy man, a happy president and happy to work with you.
"There is more work to do in the future so I am happy to announce to you that I am a candidate for re-election to the presidency of UEFA."
He confirmed that next year's congress would be held in Paris.
Asked at a news briefing afterwards what he thought his main challenges would be in his second term if he was re-elected, he replied: "The biggest challenge for me was to decide whether to run again.
"I am a happy man, I have done many things, and there are great things to do ahead and I said to myself I will be a candidate again.
"For me I had to say it today. Many people have asked me, will I stay at UEFA, will I go to FIFA, will I go to Juventus, will I be a senator, or become a Member of Parliament.
"Now I have a year to prepare my programme. This was not an electoral Congress today but I had to say I was going to run again."
Platini received a standing ovation from the floor after making his announcement and is likely to get an even bigger one in Paris in a year's time.
