Since its founding by legendary criminal attorney Edward Bennett Williams nearly fifty years ago, Williams & Connolly LLP has been regarded as one of the premier white-collar defense firms in the country. The firm has represented hundreds of individuals and business entities in government and internal investigations, military proceedings and complex white-collar criminal litigation throughout the United States. The firm has also handled extradition matters and criminal investigations abroad. See also the firm's extensive criminal defense work for Pro Bono clients.

President of the United States William Jefferson Clinton turned to Williams & Connolly to defend him in the first impeachment trial of a sitting president in over 125 years. The firm represented Vice President Dick Cheney and former press secretary Ari Fleischer in the investigation into press leaks identifying Valerie Plame as an agent of the Central Intelligence Agency. Oliver North turned to partner Brendan V. Sullivan, Jr. to represent him before Congress and in trial in federal district court over the Iran-Contra scandal.

Williams & Connolly represents individuals and corporations in all aspects of criminal investigations and trials outside of the political arena as well. The firm currently represents top executives at a global telecommunications company, a prominent investment firm and a major bank in ongoing criminal matters. The firm represented the former chief executive officer of a Fortune 500 company in his criminal trial over alleged accounting fraud.

The firm successfully defended at trial and on appeal a Republican party official accused of election day campaign interference. After receiving a split verdict in the District Court acquitting the official of the most serious charges, the firm won reversal of the remaining charges in the First Circuit Court of Appeals on the ground of jury instruction error. Most recently, the firm successfully represented a refinery company executive charged with violations of the Clean Water Act. Williams & Connolly LLP lawyers also successfully defended at trial a client acquitted of charges that he violated the trade embargo with Cuba, and a glass company executive acquitted of self dealing. In the Fifth Circuit Court of Appeals, the firm obtained the reversal of a client's conviction of violating the Clean Air Act, to name just a few examples.

The firm also represents several clients in investigations into alleged backdating of stock options; a global investment bank in an investigation into municipal bonds; a major health care public company in a multi-agency criminal investigation into alleged accounting and securities fraud, and related alleged kickback schemes; and a global accounting firm in a federal grand jury investigation into tax shelter transactions. The firm has achieved rare successes in obtaining a grant of mandamus in the court of appeals to allow for reconsideration of a motion to suppress and disqualification of government counsel; the firm also defeated a government mandamus petition opposing a transfer of venue and obtained the transfer. The firm recently argued and won on appeal that the federal government could not use a "taint team" of prosecutors to conduct a privilege review of documents subject to a grand jury subpoena directed to a third party, an issue of first impression in the federal appellate courts.

Williams & Connolly has a well-deserved reputation for zealously defending the interests of its clients. Because of the firm's vigorous representation of its clients, many are never charged, and many of the firm's greatest successes have been in investigations that never became public and therefore cannot be identified here.