White was confirmed by a unanimous voice vote in the Senate, an indication of broad bipartisan support. The Senate Banking Committee voted 22-1 to approve her nomination last month, with the only no vote coming from Sen. Sherrod Brown (D-Ohio).
Brown has been critical of federal officials in general for not being tougher on Wall Street.
White made a name for herself as the first woman to serve as U.S. attorney for the Southern District of New York. From 1993 to 2002, White aggressively prosecuted insider traders, drug traffickers and terrorists, including those involved in the 1993 World Trade Center attack and the 1998 bombings of two U.S. embassies in Africa.
She becomes the first former prosecutor to chair the SEC. But the job involves more than enforcement. The SEC is implementing dozens of new regulations as part of the 2010 overhaul of financial rules.
“The SEC needs a strong leader in place as it works to implement Wall Street reform, and that is exactly what the commission is getting with Mary Jo White,” Senate Banking Committee Chairman Tim Johnson (D-S.D.) said.
Some senators raised potential conflict of interest issues at her confirmation hearing.
After leaving the U.S. attorney's office, White took a job at a top New York law firm representing some major Wall Street firms and figures. They included former Goldman Sachs Group Inc. director Rajat Gupta and former Bank of America Corp. Chief Executive Ken Lewis.
But White apparently allayed the concerns of senators, promising tough enforcement and saying, "the American public will be my client."
"Mrs. White has an impressive record in both the public and private sectors," Sen. Jerry Moran (R-Kansas) said Monday after her confirmation.