Clinton, D-N.Y., quietly submitted her memoir deal for the committee's approval Jan. 11, almost a month after she made the lucrative agreement with New York-based publisher Simon & Schuster. (Simon and Schuster's parent company is Viacom, which also owns CBSNews.com.)
Clinton was notified that the committee approved the deal Tuesday.
"I am pleased that the Senate Ethics Committee has found that my agreement with Simon & Schuster fully complies with the Senate ethics rules," Clinton said in a statement.
Clinton did not have to obtain the committee's approval for the deal, which was agreed before she was sworn in as a senator. She chose to submit the matter to remove questions surrounding it, aides said.
While Republican criticism for the former first lady's book deal has been muted, watchdog groups questioned its ethics. Gary Ruskin of the Congressional Accountability Project wrote a Dec. 18 letter to Clinton urging her to submit the deal to the committee and asking her to forsake an advance in favor of straight royalties.
Asked at the time if she would seek ethics committee approval, the Clinton camp said only that she was complying with ethics guidelines.
Ruskin said the committee's approval of Clinton's book deal proves the ethics guidelines have no teeth.
"This is part of the liberal permissiveness about public corruption of our ethics laws that has been embraced by both parties," Ruskin said Wednesday.
There was no comment from the ethics committee.
Controversy over Newt Gingrich's $4.5 million book deal prompted the House to revise its ethics guidelines to bar members from accepting advances, but there is no similar ban in the Senate as long as the deal is "usual and customary."
Clinton's $8 million advance is believed to be the second highest ever for a nonfiction book, trailing only the $8.5 million received by Pope John Paul II.
Her lawyer, Bob Barnett, said Wednesday that Clinton already received one-third of the advance on royalties, or about $2.7 million. The rest of the advance is paid out is to be paid out over several years.
The book is to be published in early 2003.
Clinton has yet to begin writing the memoir, which will focus on her eight tumultuous years in the White House. She also has yet to select a collaborator from the 40 people who have applied for the job.