Emanuel, who served as a political and policy aide in the Clinton White House before running for Congress, weighed the family and political considerations before accepting. He will have to resign his seat, relinquish his position in the House Democratic leadership and put aside hopes of becoming House speaker.
Democratic officials who disclosed Obama's acceptance did so on the condition of anonymity to avoid angering Obama's team; it had not planned to announce the chief of staff position on Thursday.
In offering the White House post to Emanuel, Obama turned to a fellow Chicago politician with a far different style from his own, a man known for his bluntness as well as his single-minded determination.
House GOP leader John Boehner of Ohio called Emanuel "an ironic choice for a president-elect who has promised to change Washington, make politics more civil, and govern from the center."
Before accepting the job, Emanuel told Chicago's WLS-TV that he was honored to be considered but needed to weigh the impact on his family.
"I have a lot to weigh: the basis of public service, which I've given my life to, a career choice. And most importantly, what I want to do as a parent," Emanuel said in an interview aired Wednesday. "And I know something about the White House. That, I assume, is one of the reasons that President-elect Obama would like me to serve. But I also know something about what it means to a family."
As word of Emanuel's acceptance spread Thursday, Obama was meeting privately in Chicago with U.S. intelligence officials preparing him to be commander in chief and transition team leaders tasked with building his entire administration in 10 short weeks.
The president-elect planned his first public appearances since his victory for Friday.
Aides said he planned to meet with economic advisers to discuss the nation's financial woes that Americans listed as their top concern on Election Day, and also was slated to talk to the news media afterward. They also said Obama and his wife, Michelle, will visit the White House on Monday at President Bush's invitation.
Obama advisers said he was selecting the leaders of the new government with a sense of care over speed, with no plans to announce Cabinet positions this week.
Aside from Emanuel, several Obama aides said other White House officials were being lined up, including Robert Gibbs as the likely pick for press secretary. Gibbs has been Obama's longtime spokesman and confidant and was at Obama's side from his 2004 Senate campaign through the long days on the presidential campaign trail.
Obama planned to stay home through the weekend, with a blackout on news announcements so that he and his staff can get some rest after a grueling campaign and the rush of their win Tuesday night. He is planning a trip to Hawaii in December to get away with his family before their move to the White House - and to honor his grandmother, who died Sunday at her home there.
Obama began Thursday as he usually does, with a workout. Later, he planned to visit with the transition team he officially announced Wednesday but had been under way for weeks. Officials had kept deliberations under wraps to avoid the appearance of overconfidence in the weeks leading to Tuesday's election.
He also spent time at the FBI office in Chicago, a secure location for him to receive his first president's daily brief. The document is mostly written by the Central Intelligence Agency and includes the most critical overnight intelligence. It is accompanied by a briefing from top intelligence officials that typically lasts 45 minutes to an hour, although Obama's first is expected to be longer.
Liz Sidoti reported from Washington. Associated Press Special Correspondent David Espo in Washington and AP reporter Beth Fouhy in Chicago contributed to this report.