Chamber also approves Commerce Secretary Gary Locke as the next ambassador to China.
The Senate voted 100-0 on Wednesday to confirm Robert Mueller to remain as director of the FBI for two more years.
President Obama had previously requested that Mueller's term be extended for two years in order to help ensure continuity in his national-security team. Mueller had been under a 10-year term that would have expired on August 3.
But some Republican senators were hesitant to simply extend Mueller's term for two years, fearful that doing so might not be constitutionally allowed. Instead, senators worked out a process under which they passed legislation allowing Obama to renominate Mueller for two more years. Obama signed the bill on Tuesday and formally renominated Mueller.
The Senate on Wednesday also approved Commerce Secretary Gary Locke to be the next ambassador to China. Locke, who was confirmed on a voice vote, will be the first Chinese-American to assume that post.
Despite concerns by civil rights advocates and some lawmakers that the government has at times overreached and abused its law enforcement powers, Mueller enjoys widespread, bipartisan support in Congress. He is the first director to be granted an extension. If he stays on until the end of the extension, Mueller will be the longest-serving director since J. Edgar Hoover.
Speaking on the Senate floor before the vote, Senate Judiciary ranking member Charles Grassley, R-Iowa, said the FBI has its share of "black marks and skeletons in the closet." He said he was particularly concerned at how the FBI has treated whistle-blowers who report fraud and abuse. But he said those problems "are not necessarily the fault of Director Mueller."
"In 1976, following the excesses of J. Edgar Hoover, Congress limited the term of the director of the FBI to one non-renewable 10-year term … to prevent the accumulation of excess power by the director as well as to provide some political independence for the FBI," Grassley added. "However, we do live in extraordinary times and currently face unusual national-security threats."
Judiciary Chairman Patrick Leahy, D-Vt., said Mueller has guided the FBI through a major transformation since taking over the bureau in the days just before the September 11 attacks.
"Although the transformation has not been without problems, Director Mueller has consistently displayed professionalism and focus in increasing the FBI's national security and counterterrorism efforts, while still carrying out the bureau's essential law enforcement responsibilities," Leahy said.
Mueller's new term expires on September 4, 2013.