Los Angeles:
400 South Hope Street
Los Angeles, CA 90071


Seth Aronson


Seth Aronson is a partner in O’Melveny’s Los Angeles office and a member of the Securities Litigation Practice.  He served as Firmwide chair of the practice from March 2002 to March 2011 and also served as the Managing Partner of O’Melveny’s Los Angeles office from July 2000 through January 2008.  Seth defends corporations and their directors, officers and professionals in securities class actions, shareholder derivative actions, SEC enforcement proceedings, unfair competition and consumer class actions, as well as RICO and mergers and acquisitions litigation.  He is a leader in defending foreign issuers sued in the U.S. and is particularly active on behalf of Chinese companies.  Seth was the Co-Chair of the PLI’s 2011 Securities Litigation and Enforcement Institute.

Seth has been recognized by Chambers and Partners: Chambers USA - America’s Leading Business Lawyers as one of a handful of lawyers to be ranked as a leading lawyer in three categories: General Commercial Litigation (California) (“cited as ‘excellent’ on account of his highly distinguished practice”), Securities Litigation (national) (“absolutely terrific”) (“one of the driving forces behind the firm’s burgeoning representation of Chinese companies in the USA), and Securities Litigation (California; Band 1) (“a prominent figure in major securities class actions”) (“one of the best in the USA in defending [securities] suits”); named a “Top 100 Lawyer” by Daily Journal (2008) (“Around the country, he’s known as a perspicacious hard-nosed litigator who can go toe-to-toe with the most aggressive plaintiff lawyer”); listed in Legal 500 United States for his securities litigation practice; named a leading California litigator and a “National Litigation Star,” and ranked among the top 50 securities litigators by Benchmark Litigation; listed as a “Highly Recommended”  lawyer in Dispute Resolution by PLC Which Lawyer?; recognized by Who’s Who Legal: California (2009) as one of the top 34 commercial litigators in the state (“one of the go-to guys for securities litigation and was consistently endorsed by some of the practice area's heavy-hitters”); recognized by the Los Angeles Business Journal (2007) in its “Best of the Bar” special report as one of the top 12 litigators among Los Angeles County’s 48,000 lawyers; recognized by the Los Angeles Daily Journal (2005) as one of the top 30 securities litigators in California; named by Lawdragon as one of the “500 Leading Lawyers in America” (2006-09), as well as one of top “100 Securities Litigators You Need to Know” (2008); and is listed in The Best Lawyers in America© (2006-16) in four categories: Bet-the-Company Litigation, Commercial Litigation, Litigation - Regulatory Enforcement (SEC, Telecom, Energy), and Litigation - Securities, and earned the singular distinction of 2013 Los Angeles Securities Litigation “Lawyer of the Year”.

Illustrative Professional Experience

  • Lead trial counsel for a computer hardware company in Federal Court action against computer dealers, distributors, former employees and others for RICO violations and fraud. Successful jury verdict
  • Trial counsel for Fortune 500 company defending action to enforce exercise of stock options.  After three-week jury trial, jury returned defense verdict. (Daily Journal “Top Ten Defense Verdicts of 2002”)
  • Trial counsel in successful defense of federal class action securities case
  • Defense counsel in a variety of shareholders' class and derivative actions, including actions representing major investment banking firms, utility companies, large industrial companies and national auditing firms
  • Counsel in the defense of professionals and directors of financial institutions in actions brought by federal regulatory agencies
  • Counsel to a prominent Los Angeles law firm and a former Commissioner of the California Department of Corporations, and defense liaison counsel, in publicized securities and financial fraud cases
  • Various pro bono cases, including successful Eighth Circuit appeal on behalf of a plaintiff's civil rights attorney in the Kansas City School desegregation cases
  • Defense of large retailing firms in consumer class and unfair competition actions under the California Business and Professions Code
  • Handling several high profile matters involving misdated stock options

Professional Activities

Admitted to Practice,  US District Court, Central, Southern, and Northern Districts of California; US Court of Appeals, Eighth and Ninth Circuits; US Supreme Court
Board of Governors,  Association of Business Trial Lawyers (1992-2002) (President, 2001-02)
Board of Directors,  Los Angeles Area Chamber of Commerce (2003-2008); Ninth Circuit Historical Society (2000-present); Legal Aid Foundation of Los Angeles (1993-2000) (President 1998-1999); California Club (Secretary, 2007-2008); Southern California Leadership Network (2009)
Board of Advisors, UCLA School of Public Affairs (2001-2011)
Board of Overseers,  Loyola Law School (2001-present)
Chair, Los Angeles County Bar Association; Complex Courts Committee (2000-2005)
Author,  “Understanding the Laws Behind Securities Transactions” (chapter “A Closer Look at the Laws Governing Securities"), Aspatore Books (2006); “Litigating the Class Action Lawsuit in California,” (chapter “Summary of Selected Topics of California Class Action Law”), National Business Institute (2000); “Emerging Theories of Liability: Corporate Fiduciaries Who Leave to Compete With Their Former Employers,” The Journal of Proprietary Rights, Prentice Hall (April 1991)
Coauthor,  “A Decade in Review: The Securities Litigation Uniform Standards Act,” The Review of Securities & Commodities Regulation (Vol. 42, No. 8, 4/15/2009); “Future of Advancement and Indemnification Rights,” Securities Law360 (7/10/2009); “Shareholder Derivative Actions: From Cradle to Grave,” Practising Law Institute (2006, 2007, 2008, 2009, 2010, 2011); “Recent Developments and Trends in Securities Litigation,” Practising Law Institute (2008, 2009, 2010, 2011); “Securities Litigation Uniform Standards Act: 2008 Update,” Practising Law Institute (2008, 2009); “Preemption of ‘Holder’ Class Actions Under SLUSA,” The Review of Securities & Commodities Regulation (Vol. 39, No.15, 9/6/2006); “Courts Deny Plaintiffs Over Section 304 Suits,” International Financial Law Review (March 2006); “Current Issues Under the Securities Litigation Uniform Standards Act,” The Review of Securities & Commodities Regulation, (Vol. 37, No. 6, 3/31/2004); “Recent Developments in Shareholder Derivative Actions,” Practising Law Institute (2001, 2005); “Securities Litigation Uniform Standards Act – The Year in Review,” Practising Law Institute (2003); “Liability for Exchange Act Violations,” Practising Law Institute (2005); “Litigation Under the Securities Litigation Uniform Standards Act,” Practising Law Institute (2001, 2002); “Current Issues Under the Securities Litigation Uniform Standards Act,” Practising Law Institute (2005, 2006, 2007); “Effective use of Damages Experts in Securities Class Actions,” Practising Law Institute (2002); “In Re Silicon Graphics: The Ninth Circuit Raises the Bar for Pleading Private Securities Fraud Complaints,” Practising Law Institute (2000)
Lecturer and Panelist,  Various litigation topics, including programs by the Practising Law Institute; American Bar Association; Los Angeles County Bar Association; Association of Business Trial Lawyers; Directors Roundtable; Association of Corporate Counsel; CLE International, National Business Institute; Federal Bar Association; and UCLA Law School
Recipient,  On behalf of the Firm, the Constitutional Rights Foundation’s 1992 Mentor Firm of the Year Award
Member,  Los Angeles County Bar Association, Litigation Section Executive Committee (1999-2003)

Loyola University,  J.D., 1981

Ohio University,  B.B.A., 1978