Freeh's endorsement came during the second and final day of confirmation hearings before the committee.
As the panel questioned witnesses, Holder met with Sen. Mel Martinez, a Republican. Martinez issued a statement after the hearing saying he would vote for Holder.
Martinez's support, combined with that of Sen. Orrin Hatch, a Republican, should give Holder enough votes to avoid a challenge, assuming all the Senate Democrats support him.
"The prospects are probably good that he will be confirmed," said Sen. Jeff Sessions, a Republican. No Republican senator has yet come out against the nominee.
At the confirmation hearing, Freeh said Holder had made "terrible mistakes" leading up to President Bill Clinton's pardon of fugitive financier Marc Rich. Freeh called the Rich pardon "a corrupt act" but said the corruption was not Holder's.
"I don't think it's fair to put that blame totally on Eric Holder," said Freeh. "He takes responsibility and he will never make that mistake again."
Holder was also supported at the hearing by Frances Townsend, who was President George W. Bush's homeland security adviser.
She said she does not expect to agree with every decision he would make as the nation's top law enforcement officer, but believes his choices will be fair and honestly made.
"I know Eric to be an honest, decent man of the highest ethical standards," she said.
Senators then heard emotional testimony from Joseph Connor, the son of a man slain in a 1975 bombing in New York City by a militant Puerto Rican independence group called the Armed Forces for National Liberation.
President Bill Clinton granted clemency to 16 members of that group, and Holder has been criticized for his role in the decision.
Connor urged lawmakers to oppose "anybody who would be soft on terror."
Holder "never talked to us," Connor said, urging lawmakers not to confirm "this man who recommended playing Russian roulette" with American lives by releasing unrepentant terrorists.
The witness testimony lasted two hours, and the committee was expected to vote on Holder's nomination next week.
In his appearance before the committee a day earlier, Holder said the president's decision on the FALN members was "reasonable."
Most of his testimony, though, focused on how he would oversee U.S. legal and counterterrorism policy.
Holder declared waterboarding to be a form of torture, and outlined numerous ways in which the incoming Obama administration will break sharply with the Bush administration's counterterrorism policies.
The 57-year-old former prosecutor who was deputy attorney general from 1997 to 2001 pledged to shut down the U.S. naval prison at Guantanamo Bay, Cuba, in part by sending detainees to trial in the United States, and restore the Justice Department's reputation of independence from political interference.