When he announced he planned to take another bite at the presidential apple last year, he said his decision wasn't about one person, but "about the cause of American freedom and greatness," saying he was concerned that the country was on "a dangerous course" because of Washington politics, particularly during the last two years during the administration of President Barack Obama.
Romney sought the Republican presidential nod in 2008, only to bow out to eventual GOP candidate John McCain, the senator from Arizona.
If elected, Romney would be the first Mormon to occupy the White House.
Romney, born in a Detroit suburb, graduated from Brigham Young University and completed law and business degrees in four years at Harvard before beginning his swift climb up the corporate ladder.
Romney entered the management consultant arena in 1977 with Bain & Co. of Boston, where he eventually served as chief executive officer. He also co-founded and led the spin-off, Bain Capital, a private equity investment firm.
He waged an unsuccessful challenge to Sen. Edward M. Kennedy in the 1994 U.S. Senate election.
Romney was appointed in 1999 to organize and steer the 2002 Winter Olympics as president and chief executive officer of the Salt Lake Organizing Committee, resurrecting it from the brink of financial collapse. Romney donated to charity the $1.4 million in salary and severance payments he received for his three years as president and chief executive officer and contributed $1 million to the Olympics.
Romney tried during his 2008 bid to assuage voter concerns his faith would influence his presidency, much as President John Kennedy, a Catholic, did in the 1960s. Romney was active in his faith, acting as a local leader and taking a hands-on role in various activities, including visiting the sick and counseling burdened church members.
"If I am fortunate to become your president, I will serve no one religion," Romney said during a December 2007 speech in Texas. "A president must serve only the common cause of the people of the United States."
Saying America needs "jobs -- lots of jobs" during his acceptance speech during the Republican National Convention in August in Tampa, Fla., Romney pledged to create 12 million jobs through a five-step plan.
First, North America will be energy independent by 2020 by "taking full advantage of our oil and coal and gas and nuclear and renewables."
Next, America's workers will get the skills they need for jobs now and in the future.
Third, new trade agreements will be reached that tip the balance in favor of the United States.
"And when nations cheat in trade," he vowed, "there will be unmistakable consequences."
The fourth element is to assure all entrepreneurs and job creators their investments in the United States "will not vanish as have those in Greece. We will cut the deficit and put America on track to a balanced budget."
Finally, a Romney presidency "will champion small businesses, America's engine of job growth."
He said taxes on business would be reduced, not raised, and regulations that hurt small businesses would be simplified and modernized.
Romney also promises that his first official act would be to repeal the Affordable Care Act, Obama's signature healthcare reform law that has been dubbed "Obamacare."
While governor of Massachusetts, Romney worked with a Democrat-led Legislature to enact the state's near universal health insurance coverage plan.
Romney married Ann Davies, whom he met in high school, in 1969. They have five sons and 18 grandchildren.