Louis Cohen is a senior counsel in the firm's Litigation/Controversy Department, and a member of the Appellate and Supreme Court Litigation Practice Group. He joined the firm in 1967. Mr. Cohen served as Deputy Solicitor General of the United States from 1986-1988, and focuses on US Supreme Court and other appellate litigation and corporations law. Mr. Cohen’s appellate practice has included more than fifty cases on the merits in the US Supreme Court and a large number of cases in the courts of appeals. He has argued sixteen cases in the Supreme Court, winning fifteen.


Mr. Cohen’s victories before the Supreme Court include such significant cases as the City of New York v. Clinton (the Line Item Veto case), US Term Limits, Inc. v. Thornton (invalidating congressional term limits), and Cargill v. Monfort (predatory pricing under the Clayton Act). Other Supreme Court cases in which he has participated include: Regional Rail Reorganization Act Cases (constitutionality of a reorganization statute); Piper v. Chris-Craft (interpretation of the Williams Act); Basic v. Levinson (materiality issues under the federal securities laws); Carpenter v. United States (Rule 10b-5; wire fraud); and Norwest Bank v. Ahlers (priorities under the Bankruptcy Code).

Mr. Cohen’s court of appeals cases include arguments on behalf of Bear Stearns in deKwiatkowski v. Bear Stearns (2d Cir. 2002); Sears Roebuck in Bolin v. Sears Roebuck & Co., 231 F.3d 970 (5th Cir. 2000); Painewebber Group in Painewebber v. Zinsmeyer Partnership Trust, 187 F.3d 988 (8th. Cir. 1999); First Commonwealth Savings Bank in United States v. John C. York, et al., 112 F.3d 1218 (D.C. Cir. 1997); General Electric in United States ex rel Taxpayers Against Fraud v. General Electric Company (6th Cir. 1994), and the CBS and NBC television networks in Schurz Communications v. FCC, 982 F.2d 1043 (7th Cir. 1992).

On the corporate side, Mr. Cohen has advised clients (including both for-profit and nonprofit firms) in connection with offerings of securities, mergers and acquisitions, purchases and sales of businesses, proxy fights, tender offers, corporate restructurings and liquidations.

Professional Activities

Mr. Cohen is a past winner of the Public Policy Award of the National Trust for Historic Preservation and of the Pro Bono Advocacy Award of the ACLU Foundation of Southern California. He is a member of the American Law Institute and the American Academy of Appellate Lawyers. He has served as National Chair of The Harvard Law School Fund. He has taught Corporate Finance courses at Harvard University and Stanford University, and Securities Regulation courses at George Washington University.


Recent Highlights

Mr. Cohen’s Supreme Court victories include Enron Power Marketing, Inc. v. FERC (2002) (non-discriminate access to the electric grid), and The Wharf (Holdings) Ltd. v. United International Holdings, Inc. (2001) (Breach of SEC Rule 10b-5).


  • Selected by peers for inclusion in the 2005-2022 editions of the Best Lawyers in America in the areas of appellate law, commercial litigation (2006, 2008–2023), M&A (2005–2016), business litigation, and corporate and securities law (2005–2006, 2008–2023)
  • Selected for inclusion in the 2012-2016 Washington DC Super Lawyers lists
  • Featured in an American Lawyer article identifying leading litigation departments (2002)
  • "Highly recommended” in PLC's 2003/04 Dispute Resolution Global Counsel Handbook - Public Policy Award
  • National Trust for Historic Preservation - Public Policy Award
  • Pro Bono Advocacy Award, ACLU Foundation of Southern California

Insights & News


  • Education

    • LLB, Harvard Law School, 1966

      magna cum laude
    • University of Oxford, Wadham College

      Henry Fellow
    • AB, Harvard University, 1962

      magna cum laude
  • Admissions

    • District of Columbia

    • US Supreme Court

  • Government Experience

    • Department of Justice

      Office of the Solicitor General

      Deputy Solicitor General