The former world number one and U.S. Open champion said he realised during his first-round victory over Rhyne Williams that he had lost the desire to remain on tour.
"I just feel like it's time," Roddick, who celebrated his 30th birthday on Thursday, said.
"I've always wanted to, in a perfect world, finish at this event. I have a lot of family and friends here.
"I thought all year I would know when I got to this tournament. When I was playing my first round, I knew. Playing here, I don't know what it was.
"I couldn't imagine myself being there another year."
In Image: Andy Roddick returns a shot to Rhyne Williams at the 2012 US Open tennis tournament, Tuesday, Aug. 28, 2012, in New York.