Main Menu
{ Banner Image }

Daniel M. Sullivan



Daniel Sullivan’s practice focuses on complex commercial litigation, appeals, and transnational litigation. Daniel was named a New York Law Journal Rising Star in 2015. Before joining Holwell Shuster & Goldberg in April of 2014, Daniel was a litigation associate in the New York office of Gibson, Dunn & Crutcher LLP.

Before entering private practice in November of 2010, Daniel served as a law clerk to the Honorable Antonin Scalia of the United States Supreme Court during October Term 2009, and before that to the Honorable Diarmuid F. O’Scannlain of the United States Court of Appeals for the Ninth Circuit during the 2008-2009 year.


Notable Cases

Notable Cases

  • Trustees in RMBS putback litigation in New York state and federal court, handling briefing, discovery, expert preparation, trial preparation, and appellate briefing.
  • Senator Ted Cruz in ongoing ballot eligibility challenges in New York, successfully defending dismissal of challenge on appeal in New York State court. Daniel represents the Senator in his individual capacity and not on behalf of HSG.
  • Former directors and an officer of a publicly traded technology services company in a putative securities fraud class action. After HSG filed a motion to dismiss, Plaintiffs dropped Securities Exchange Act claims against our clients. Decision is pending on Securities Act claims.
  • Westchester County regarding legal and constitutional issues in federal appellate and district court proceedings arising out of the settlement of a Qui Tam action against the County.
  • Clients in a wide variety of industries and circumstances regarding appellate, constitutional, and other legal issues arising in potential or pending state and federal litigation. Recent examples include advising a hedge fund regarding Supreme Court litigation related to the fund’s interests, evaluating RICO claims arising out of the Flint water crisis, and advising a real estate developer regarding the constitutionality of state taxation laws.
  • Auto parts manufacturer Hilite International in a successful post-trial appeal in the Federal Circuit of patent claims involving variable valve timing in automobile cam phasers. Obtained reversal of trial judgment against client on the grounds that the patent at issue was invalid.
  • Pro bono client in immigration appeal in the Ninth Circuit raising novel issues of the retroactive application of statutes. After HSG filed its opening brief, the Government agreed to a favorable remand.
  • Client in a successful petition for certiorari before the Georgia Supreme Court, involving interpretation of recent U.S. Supreme Court class action precedents, and in successful merits briefing.
  • Dow Jones in putative consumer class action alleging various common law and New York statutory claims, successfully moving for summary judgment and defending victory on appeal.
  • Filed numerous amici curiae briefs in state and federal appellate courts, including on behalf of the U.S. Chamber of Commerce and the Securities Industry and Financial Markets Association in favor of the prevailing party in Gabelli v. SEC (United States Supreme Court); on behalf of Foursquare, Kickstarter, Meetup, and Tumblr in an appeal raising the constitutionality of bulk search warrants issued by the Manhattan D.A.'s office (N.Y. Appellate Division – First Department and N.Y. Court of Appeals); and on behalf of a group of law and finance professors in the Delaware Supreme Court regarding the appropriate standard of review in appraisal litigation.
  • Employer in employment arbitrations before the Financial Industry Regulatory Authority and JAMS.
  • Numerous financial institutions in securities class actions, including, for example, in successful motions to dismiss federal securities claims arising from a multibillion-dollar unauthorized trading incident.
  • Numerous pro bono clients, including on behalf of a foundation seeking documents from New Jersey school districts in order to better advocate for schoolchildren with disabilities.

News and Writings



  • "Bristol-Myers Squibb v. Superior Court: Practical Implications and Doctrinal Conundrums," Bloomberg BNA Class Action Litigation Report (August 14, 2017) (co-author)
  • “Statutory Interpretation and the Morrison Presumption Against Extraterritoriality,” Bloomberg Law Week (March 23, 2017) (co-author)
  • "A Gentleman of the Law: A Tribute to Judge Diarmuid F. O’Scannlain," National Review Online (January 5, 2017) (co-author)
  • "Microsoft v. United States Addresses the Presumption Against Extraterritoriality in the Digital Context," The Cross-Border Cut (December 2016), Holwell Shuster & Goldberg LLP Transnational Litigation and Arbitration Briefing (co-author)
  • "BG Group PLC v. Republic Of Argentina: The Supreme Court Applies Domestic And Commercial Arbitration Principles To The Review Of Investment Treaty Arbitration Awards," Mealey’s International Arbitration Report (2014)
  • "International Aspects of U.S. Litigation," American Bar Association (co-author of chapter on personal jurisdiction (forthcoming))
  • "U.S. Supreme Court Holds that Presumption Against Extraterritoriality Applies to the Alien Tort Statute," (co-author, 2013)
  • "U.S. Supreme Court Clarifies Limitations Period for Federal Enforcement Actions," (co-author, 2013)
  • "Truly Original," The Daily (2011), A Review of Living Originalism, by Jack Balkin
  • "Big Boys and Chinese Walls," 175 University of Chicago Law Review 533 (2008)


  • Panelist, "Lifting the Corporate Veil in the Recognition and Enforcement of Foreign Judgments and Arbitral Awards: Approaches in the United States and Canada" (April 20, 2016)
Photo of Daniel M. Sullivan


  • Hon. Antonin Scalia, Supreme Court of the United States, 2009-2010
  • Hon. Diarmuid F. O’Scannlain, U.S. Court of Appeals for the Ninth Circuit, 2008-2009


The University of Chicago Law School (J.D., high honors, 2008; Order of the Coif; Appellate Advocacy Clinic, Representation in the U.S. Court of Appeals for the Seventh Circuit; Staff Member, The University of Chicago Law Review)

The University of Chicago (B.A., History (honors) and Fundamentals (honors), 2004; John M. Olin Fellow; Student Marshall; Phi Beta Kappa; Karafiol Prize for best B.A. essay in European History)

Bar and Court Admissions

  • New York
  • Supreme Court of the United States
  • U.S. Court of Appeals, Federal Circuit
  • U.S. Court of Appeals, Second Circuit
  • U.S. Court of Appeals, Fifth Circuit
  • U.S. Court of Appeals, Seventh Circuit
  • U.S. Court of Appeals, Ninth Circuit
  • U.S. District Court, Eastern District of New York
  • U.S. District Court, Southern District of New York
Back to Page