Sean Royall is a partner in Kirkland’s Dallas and Washington, D.C., offices and focuses on antitrust and consumer protection from both the litigation and government investigations perspectives.

Sean previously served in a high-level position at the Federal Trade Commission (FTC), as the Deputy Director of the FTC’s Bureau of Competition, where he played a prominent role in shaping and overseeing the agency’s antitrust enforcement agenda. In that capacity, Sean supervised the FTC’s investigations of many major mergers and acquisitions and also served as lead trial counsel in a landmark patent-related monopolization suit the FTC brought against computer chip designer Rambus Inc. Since leaving the government and returning to private practice in 2003, in addition to his decades of distinction as a nationally prominent antitrust attorney, Sean has become one of the leading lawyers in the country handling complex consumer protection matters involving marketing and advertising practices, privacy, and data security, often in relation to investigations and enforcement actions brought by the FTC and state attorneys general.

Signaling the breadth and scope of his practice, Sean recently served as lead counsel for Facebook in connection with the FTC’s extensive investigation of Facebook’s privacy-related practices (a publicly announced settlement of this matter is presently pending judicial approval) and in 2018, representing AT&T, was a member of the trial team that successfully defended the company’s $85 billion acquisition of Time Warner against the Department of Justice’s lawsuit challenging that transaction. In addition to his trial-level litigation work, Sean has handled and argued multiple appeals in circuit courts around the country.

Drawing upon his decades of experience in antitrust, consumer protection, federal court litigation, and government investigations, Sean regularly counsels clients on a wide range of strategic and compliance-related issues, including mergers, joint ventures, pricing and distribution practices, strategic patent and intellectual property issues, advertising, marketing and e-commerce strategies, data security, and privacy compliance. Sean is also a frequent author on cutting-edge legal issues arising in the highly dynamic areas in which he practices.

Sean has been ranked Band 1 in Antitrust by Chambers USA for nearly two decades, and is described by Chambers as an “extremely talented lawyer and an exceptional litigator.” He has also received multiple “Lawyer of the Year” distinctions from The Best Lawyers in America, and has been included by Law360 on a select list of national Antitrust “MVPs,” among other distinctions.


Thought Leadership

Press Mentions

“CFPB May Fill Enforcement Gap After FTC's High Court Loss,” Law360, May 6, 2021

“FTC Seeks Quick Win In False Ad Suit Against LendingClub,” Law360, April 27, 2020

“By the Numbers: 5 Practices That Could Drive Big Law in 2021,” Bloomberg Law, Dec. 23, 2020

"'Hipster Antitrust’ Comes for Joe Biden," New York Times, Nov. 13, 2020


M. Sean Royall, Richard H. Cunningham, and Olivia Adendorff, A Watershed Moment? What Comes Next for the FTC in the Wake of AMG, ABA Antitrust Magazine, August 9, 2021

M. Sean Royall, Rachael Rezabek, “The Intersection of Antitrust and the False Claims Act,” Headnotes, Dallas Bar Association, June 2021

M. Sean Royall, Richard H. Cunningham, et al., Unpacking the New FTC/DOJ Draft Vertical Merger Guidelines, WLF Legal Pulse, Mar. 9, 2020

M. Sean Royall, Richard H. Cunningham, Olivia Adendorff, and Ashley Rogers, Seventh Circuit Sets Up Potential Supreme Court Review of FTC Monetary Relief Authority, ABA Antitrust Magazine, Dec. 12, 2019

M. Sean Royall, Richard H. Cunningham, et al., Next Stop, Supreme Court? Seventh Circuit Goes Its Own Way on FTC’s Authority to Obtain Monetary Relief, WLF Legal Pulse, Sept. 3, 2019

M. Sean Royall, Richard J. Cunningham, et al., Taking Stock of FTC Cybersecurity Enforcement After the Equifax Settlement, WLF Legal Pulse, Aug. 7, 2019

M. Sean Royall, Blaine H. Evanson, et al., Ninth Circuit Judges Call for En Banc Review of FTC’s Authority to Obtain Monetary Relief, WLF Legal Pulse, Jan. 15, 2019

M. Sean Royall, Richard H. Cunningham, et al., Lessons from FTC’s Loss in, and Subsequent Abandonment of, DirecTV Advertising Case, WLF Legal Pulse, Oct. 23, 2018

M. Sean Royall, Richard H. Cunningham, and Ashley Rogers, Are Disgorgement’s Days Numbered? Kokesh v. SEC May Foreshadow Curtailment of the FTC’s Authority to Obtain Monetary Relief, ABA Antitrust Magazine, Spring 2018

M. Sean Royall and Richard H. Cunningham, Will Kokesh v. FTC Put a Kink in the Federal Trade Commission’s Disgorgement Hose? WLF Legal Pulse, July 10, 2017

M. Sean Royall, Ashley Johnson, and Jason McKenney, Antitrust Scrutiny of Pharmaceutical Product Hopping, ABA Antitrust Magazine, Fall 2013

M. Sean Royall, When Mergers Become a Private Matter: An Updated Antitrust Primer, ABA Antitrust Magazine, Spring 2012

M. Sean Royall and Adam J. Di Vincenzo, Evaluating Mergers Between Potential Competitors Under the New Horizontal Merger Guidelines, ABA Antitrust Magazine, Fall 2010

M. Sean Royall and Joshua Lipton, The Complexities of Litigating Generic Drug Exclusion Claims in the Antitrust Class Action Context, ABA Antitrust Magazine, Spring 2010

M. Sean Royall, Ashley E. Johnson & Malachi Boyuls, Change?: Merger Enforcement in the New Administration, 47 The Advocate 54, Summer 2009

M. Sean Royall, Amanda Tessar, Adam J. Di Vincenzo, Deterring “Patent Ambush” in Standard Setting: Lessons from Rambus and Qualcomm, ABA Antitrust Magazine, Summer 2009

M. Sean Royall and Adam J. Di Vincenzo, The FTC’s N-Data Consent Order: A Missed Opportunity to Clarify Antitrust in Standard Setting, ABA Antitrust Magazine, Summer 2008

M. Sean Royall and Sarah Vollbrecht, Avoiding the Scarlet "S": The Modern Challenges of Document Preservation and Destruction, The American Lawyer, June 2005

M. Sean Royall, The Art of Destruction, The American Lawyer, September 2004

M. Sean Royall, Standard Setting and Exclusionary Conduct: The Role of Antitrust in Policing Unilateral Abuses of a Standard-Setting Process, 18 Antitrust 44, 2004

D. Bruce Hoffman and M. Sean Royall, Administrative Litigation at the FTC: Past, Present, and Future, Antitrust Law Journal, 2003

M. Sean Royall & Seth M.M. Stodder, Noerr Immunity for Sponsoring Litigation: From Burlington Northern to Baltimore Scrap, 15 Antitrust 47, 2001

M. Sean Royall, Coping with the Antitrust Risks of Technological Integration, Antitrust Law Journal, 2000

M. Sean Royall, Disgorgement of Antitrust Damages, Antitrust Law Journal, 1997

M. Sean Royall, Post-Chicago Economics, 63 Antitrust L. J. 445, 1995


Global Competition Review 100, Highly Recommended (Texas), 2022

Who's Who Legal, Competition, 2021

Chambers Global, Competition/Antitrust (USA), 2020–2021

Chambers USA, Band 1 for Antitrust, 2007–2021

BTI Client Services, All-Star List, 2017

The Best Lawyers in America, Antitrust Lawyer of the Year, 2015, 2018

The Best Lawyers in America, Litigation: Antitrust Lawyer of the Year, 2019

Law360, National Antitrust MVP, 2015

National Law Journal, Mergers & Acquisitions and Antitrust Trailblazer, 2015

Benchmark Litigation, Litigation Star (Antitrust, Appellate, General Commercial)

Who’s Who Legal, Global Leader in Antitrust

LMG Life Sciences, Life Science Star in Competition and Antitrust, 2018–2019


Admissions & Qualifications

  • 1991Texas
  • 1997District of Columbia


  • University of Chicago Law SchoolJ.D.cum laude1990

    Managing Editor, University of Chicago Law Review

    Tony Patiño Fellowship

  • Texas A&M UniversityB.S., Economicsmagna cum laude1986

    Student Body President

    Alfred Chalk Award (top graduate in economics)