A couple thousand supporters trudged through icy slush to attend the outdoor ceremony at the east entrance to the Capitol. State Supreme Court Chief Justice Ronald Castille administered the oath as Corbett placed his hand on a Bible once owned by William Penn.
Corbett, the former state attorney general, said Pennsylvania faces serious challenges that include high unemployment that stood at 8.6 percent in November, government spending "beyond its means" and corruption that has eroded public trust in government, an apparent reference to the investigation of the Legislature that he launched four years ago.
"The chill that we feel today isn't solely January's wind," he said. "We gather during uncertain times and no one has been left untouched."
Corbett, wearing a long, black wool coat and no hat in temperatures just above freezing, barely smiled while delivering a speech that observers said seemed more serious than others in the recent past.
"I will honor your trust by standing firm in my guiding principle to do the right things, for the right reasons, even in the most challenging of times," he said in the speech. "And I will dedicate each and every day over the next four years to fiscal discipline and a responsible, limited government."
From Soldiers' Grove, a tree-lined mall behind the inaugural staging area, about 100 protesters could be heard chanting and blowing whistles to oppose the use of hydraulic fracturing, or "fracking," in drilling for natural gas from the rich Marcellus Shale reserve deep underground. Critics say too little is known about the health risks posed to drinking water by the huge amounts of wastewater fracking generates.
"Tom Corporate - no way, no fracking in Pa.," one activist shouted through a bullhorn.
"No doubt the First Amendment is alive and well in Pennsylvania today," Senate President Pro Tempore Joe Scarnati, who presided over the inaugural, quipped over the public-address system.
Corbett, who did not acknowledge the protesters in his speech, received substantial campaign contributions from the natural-gas industry. He has stood firmly against any new tax on natural-gas drilling, leaving Pennsylvania as the only state with significant natural gas production that does not tax it.
Corbett, 61, succeeds Democrat Ed Rendell, who stepped down after having served the maximum two four-year terms. Rendell attended the inaugural, as did former GOP Govs. Mark Schweiker, Tom Ridge and Dick Thornburgh.
Combined with the GOP takeover of the House of Representatives, Corbett's inauguration gives the Republicans control of both the executive and legislative branches, which presumably will aid Corbett as he moves to implement his agenda.
In last year's election campaign, Corbett enjoyed strong statewide name recognition largely due to the high-profile legislative probe, which has resulted in 25 arrests so far. He was elected in November on promises to cut state spending and erase a multibillion-dollar deficit without increasing state taxes or fees.
Corbett made no specific promises in Tuesday's speech, but stressed his determination to reform government, including the Legislature, and expand "choice in our education system" through taxpayer-financed alternatives for parents who want to remove their children from failing public schools.
"We must act to renew the people's trust in government. We must restore transparency, accountability and fiscal discipline," he said.
Democratic legislative leaders remain wary of potential spending cuts in programs with proven success.
Senate Minority Leader Jay Costa, D-Allegheny, said he was struck by Corbett's stated willingness to work with both parties, and that jobs programs would be a good place to start.
"I think it's common ground," Costa said. "I think we just need to realize that there are a number of programs that we have in place today that we cannot afford to cut - they've been successful."
House Minority Leader Frank Dermody, D-Allegheny, said he was concerned about continuing the funding of the adultBasic health insurance program and said cuts to education will put pressure on local school property taxes.
"We've made great strides in education," Dermody said. "We want to continue those strides."
Tom and Susan Corbett began the day by attending a Roman Catholic Mass at the Cathedral of St. Patrick, a block from the state Capitol.
Prior to Corbett's inauguration, his running mate - lawyer and former Bucks County commissioner Jim Cawley - was sworn in as lieutenant governor inside the packed chambers of the state Senate, where he once worked as a staff aide.
Cawley said the results of the November election show voters want state government to build a better relationship with the business community, change public-sector pensions and develop a "fair, equitable and productive legal system."
"The message they sent was that what's been done in the past isn't working," Cawley said.
The new governor and his supporters planned to celebrate Tuesday night at an inaugural ball at the Pennsylvania Farm Show Complex and Expo Center. It was expected to feature three live bands, 30 bar stations and five regionally themed pits with chefs preparing modern-day twists on distinctly Pennsylvania foods from venison pot pies to flaming mushrooms.
Associated Press writers Mark Scolforo and Marc Levy contributed to this report.