Christie had scheduled a press conference at 1 p.m. at the New Jersey Statehouse.
"Now is not my time to run," he said, reports The New York Times.
Christie also quipped that the state was "stuck" with him, reports MSNBC.
For much of the past year, Christie has insisted that he won't run, but he continued to meet with donors and made speeches on topics such as "Real American Exceptionalism" at the Ronald Reagan Library in California.
Though at first, Christie made colorful statements such as "What do I have to do short of suicide to convince people I'm not running?", in the past few weeks Christie has made clear that he was seriously considering a run, reports CBS News.
If Christie did enter the race, he would be in 4th place with 11 percent of the national GOP vote, reports Politico. This would start him out tied with Ron Paul, according the a poll by Washington Post/ABC News. Christie would only be a few points below Perry and Herman Cain. The current first place candidate is Mitt Romney.
Christie has found himself at odds with much of the Republican base for his comments on climate change (he believed it was real), and his belief that allegations of "creeping Sharia law" was "crazy" and "crap." However, his running had serious implications for the future of the Republican party.
With Christie out of the running, the rivalry between Rick Perry and Mitt Romney should quickly resume, reports The New York Times.
The Republican race has been defined by rises and falls, and Christie's decision, reports the Washington Post, will be the last major domino. Former Alaska Gov. Sarah Palin has yet to make a decision about her plans for 2012. However, according to polling she would enter the race as a second-tier candidate.