O’Melveny Worldwide

Daniel J. Tully is an experienced litigator with a broad practice focused on securities, financial services, and complex business litigation, including the defense of federal securities class actions and fiduciary duty litigation. Dan also has substantial experience representing and advising public and government entities on matters involving federal constitutional and administrative law. He has authored briefs at all levels of state and federal courts, including an amicus brief in the Supreme Court’s DACA decision, Regents of the University of California v. Department of Homeland Security. Dan has also led teams in developing and executing case strategy through all stages of litigation, including pre-trial fact investigation and discovery, trial witness preparation, and post-trial motion practice and appeals. Dan is also an active member of O’Melveny’s pro bono practice, where he focuses on constitutional and immigration law.

Prior to joining O’Melveny, Dan served as a judicial law clerk for the Honorable Margaret M. Morrow of the United States District Court for the Central District of California. While in law school, Dan participated in the UCLA Law Ninth Circuit Appellate Advocacy Clinic. Under the supervision of O’Melveny attorneys, Dan briefed and argued an appeal on behalf of an indigent prisoner for various constitutional violations, successfully obtaining reversal and remand from the Ninth Circuit. He also served as managing editor of the Journal of International Law and Foreign Affairs, articles editor of the UCLA Journal of Law and Technology, and as a writing advisor for the first year Lawyering Skills Program. Dan was also actively involved in UCLA Law’s Moot Court Honors Board and represented UCLA Law in national appellate advocacy competitions.

  • Obtained dismissal of putative class action against national bank challenging fee policies.
  • Obtained dismissal of Section 10(b) claim against a US-listed Chinese online service provider and its CEO in one of the first shareholder class actions seeking to exploit China’s ban on initial coin offerings.
  • Represented one of the nation’s largest banks in numerous consumer banking putative class actions.
  • Litigated to favorable settlement lawsuit against global investment firm for breach of fiduciary duty under ERISA.
  • Part of trial team for major studio that prevailed at arbitration in a lease and termination fee dispute.
  • Part of trial team for luxury mobilehome park owner who obtained a multi-million dollar jury verdict against a municipality for a regulatory taking under the Fifth Amendment to the US Constitution.
  • Advised major motion picture studio regarding contract and First Amendment issues.
  • Advised a large government entity on immigration issues, including filing numerous amicus briefs to further the entity’s support of immigrant residents and local law enforcement priorities.
  • Represented an asylum seeker in proceedings before the Board of Immigration Appeals and the US Court of Appeals for the Ninth Circuit.
  • Represented reproductive healthcare nonprofit in a challenge to state abortion restrictions.
  • Drafted amicus brief in US Supreme Court in case reviewing dismissal of law enforcement excessive-force claims.


Bar Admissions

  • California
  • Illinois

Court Admissions

  • US Court of Appeals, Ninth Circuit 
  • US District Court, California Central
  • US District Court, California Eastern
  • US District Court, California Northern
  • US District Court, District of Columbia
  • US Supreme Court


  • University of California at Los Angeles, J.D.: Order of the Coif; Michael T. Masin Scholar; Managing Editor, Journal of International Law and Foreign Affairs; Articles Editor, UCLA Journal of Law and Technology; Vice Present, UCLA Law Moot Court Honors Board; Writing Advisor for Lawyering Skills Program
  • University of Pittsburgh, B.A., Political Science and Business: summa cum laude

Professional Activities


  • Honorable Margaret M. Morrow, US District Court for the Central District of California


  • Honorable Gary A. Feess, US District Court for the Central District of California