The race attracted an unusual amount of attention because Christie is believed to be a likely contender for the Republican presidential nomination in 2016.
Christie won more than 60 percent of the vote, one of the biggest margins in the history of the state, NJTV reported. But he fell short of Gov. Thomas Kean's resounding 71 percent victory in 1985, when the Republican governor carried every county and all New Jersey's major cities.
Voters also failed to follow Christie's lead down the ballot. While the final results were still unclear, the Democrats appeared to have retained control of the state legislature and a referendum raising the state's minimum wage and tying it to inflation passed by a large margin.
In his victory speech at the Asbury Park Convention Center, Christie insisted his main interest is in governing New Jersey. He said his first goal is "to get the job done."
"As long as I'm governor that job will always be finished," he said.
But he also hinted at a national agenda.
"I know that a dispirited America, angry with their government in Washington, looks to New Jersey to ask, 'Is what I think is happening really happening?'" he said, saying that he has been building bridges across party, ethnic and racial lines.
Buono conceded about an hour after the polls closed. In a fiery speech, she called New Jersey one of "the last vestiges of old boy machine politics" and talked about "back-room deals," The Star-Ledger of Newark reported.
Late polls showed Christie winning by anywhere from 20 to 36 percentage points.
After a heavy schedule of campaign events in the final days, Christie seemed relaxed early Tuesday as he voted in Mendham with his wife, Mary Pat, The Star-Ledger said.
Christie, 51, was elected governor in 2009 after serving as a Morris County freeholder and from 2002 to 2008 as U.S. attorney for New Jersey. He led a prosecutor's office involved in a number of high-profile cases, including political corruption and organized crime.
The governor was an early backer of former Massachusetts Gov. Mitt Romney, the Republican presidential nominee in 2012. But when Superstorm Sandy hit New Jersey a few days before the election, Christie literally embraced President Obama, a move that angered many Republicans but burnished his credentials as someone willing to reach across the political divide.
Buono, 60, is a lawyer like Christie. She served in the state Assembly for almost a decade before winning election to the Senate in 2001.
Buono lives in Metuchen, a central New Jersey suburb. She and her husband have six children.
Interpol investigating stolen passports on missing flight
Susan Sarandon 'very excited' about daughter's pregnancy