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Tadler Law LLP is a women-owned litigation boutique that represents consumers, investors, and businesses in complex and class action litigation nationwide.

Founded in 2019 by Ariana J. Tadler, a leading plaintiffs’ litigator and a pioneer in e-discovery law, the firm offers 20-plus years of litigation experience in the areas of complex and class action litigation, e-discovery, contract negotiation and legal risk consulting.Tadler Law partners with law firms and clients looking to diversify their legal teams and offers the highest level of litigation experience.

Capitalizing on decades of courtroom experience in complex and class action cases, the firm regularly litigates high-profile, national and international matters, involving Fortune 100 parties represented by top AmLaw firms. The firm is known for deploying state-of-the-art technology to efficiently achieve creative and effective solutions for its clients. The firm advises high-net-worth investors, investment institutions, middle-market companies, municipalities, and consumers in a variety of matters. Tadler Law also served as special discovery counsel on behalf of parties to complement their in-place litigation teams.


Antitrust Litigation: Tadler Law’s team is well versed in litigating national antitrust matters in various industries, including the pharmaceutical industry. The firm’s attorneys frequently expose anticompetitive conduct such as price-fixing, pay-for-delay, monopolization, tying arrangements, exclusive dealing, patent suppression, and refusals to deal. To that end, partners A.J. de Bartolomeo and Brian Morrison and senior associate Joann Militano are part of the Direct Purchasers’ leadership team in In re Glumetza Antitrust Litigation, No. 3:19-cv-5822 (N.D. Cal.), a case alleging that defendants violated federal antitrust laws by engaging in a scheme to charge supracompetitive prices for the diabetes prescription drug Glumetza. Ms. de Bartolomeo was appointed to the Direct Purchaser’s Plaintiffs’ Executive Committee.

Complex Litigation: Tadler has successfully represented businesses, investors, and municipalities in complex cases involving a wide range of claims.

Tadler Law attorneys have:

  • represented a corporation in an accounting negligence case against PricewaterhouseCoopers
  • represented mid-size and large corporations in contractual disputes and other complex matters
  • managed significant internal investigations and other review projects

Consumer Litigation: The firm’s lawyers have protecting consumers from fraudulent and deceptive practices. Among other types of cases, the firm has led class actions challenging the use of “natural” labeling on food products made from bioengineered crops (GMOs). E.g., In re Conagra Foods, Inc., No. 11-05379 (C.D. Cal.) (Class counsel; multi-state class certified; class certification affirmed by Ninth Circuit; petition for writ of certiorari denied by U.S. Supreme Court; settlement pending final approval); Frito-Lay North America, Inc. “All Natural” Litigation, No. 12-MD-02413 (E.D.N.Y) (settled); In re General Mills, Inc. Kix Cereal Litigation, No. 2:12-cv-00249 (KM)(JBC)(D.N.J.) (Court-appointed interim co-lead class counsel; case currently stayed).

Data Breach and Privacy Litigation: The firm has made its mark litigating class actions alleging massive data breaches and other violations of consumers’ personal and data privacy. It has spearheaded numerous highly technical cases and has successfully advanced novel legal theories to protect consumers from ever-evolving cybersecurity and data privacy threats.

Equal Pay Litigation: Tadler Law is currently representing United States Women’s National Soccer Team (“WNT”) former goalkeeper Hope Solo in her gender-based employment discrimination lawsuit against the United States Soccer Federation (“the Federation”). Solo v. United States Soccer Federation, No. 3:18-cv-05215-DMR (N.D.Cal.). Partner A.J. de Bartolomeo recently joined Solo’s legal team to allege that significant pay disparities exist between the U.S. Men’s National Soccer Team (“MNT”) and the WNT. According to the suit, contrary to the assertions of the Federation, there are no legitimate, non-discriminatory reasons for this gross disparity of wages, nor can it be explained away by any bona fide seniority, merit or incentive system, or any other factor other than sex.

E-Discovery: Ariana J. Tadler pioneered the development of an e-Discovery Practice Group at a plaintiffs’ firm. She assembled and trained a dedicated team to meet the e-Discovery demands of complex litigation and developed some of the most exceptional e-Discovery capabilities among U.S. law firms. Established more than 15 years ago, that e-Discovery practice grew extensively, and today, Tadler Law offers clients the ability to go toe-to-toe with adversaries in the fast-evolving e-Discovery climate. This multidisciplinary group offers clients a full array of counsel services relating to discovery strategy, data preservation, data collection and storage, sophisticated data search and analysis, production, and computer forensic investigation, as well as training on e-Discovery issues, including application of the latest amendments to the Federal Rules of Civil Procedure, local rules, and state law.

All Tadler Law lawyers are trained and experienced in the field of e-Discovery and are regularly called on by attorneys and courts to oversee complex discovery in high-stakes litigation.

Financial Fraud and Whistleblower Representation: Several members of the Tadler Law team have a long history of aggressively pursuing cases on behalf of institutional investors, individuals, and other victims against companies committing securities fraud or other financial wrongdoing. They have worked to secure recoveries of hundreds of millions of dollars on behalf of investors, over the course of their collective careers. Additionally, our team is well versed in representing financial whistleblowers with the SEC.


Tadler Law LLP is metro ranked in 1 practice areas. Best Law Firms rankings are based on a rigorous evaluation process.

Read how Best Law Firms ranks firms

Metro Rankings

Long Island, NY
Tier 1 for Mass Tort Litigation / Class Actions - Plaintiffs


Metro Rankings

Long Island, NY
Tier 1 for Mass Tort Litigation / Class Actions - Plaintiffs

Practice Areas

The below are areas of legal specialty volunteered by the firm and do not designate a specialty in which a Best Law Firms ranking is held.
  • Antitrust Law
  • Commercial Litigation
  • Consumer Law
  • Electronic Discovery and Information Management Law
  • Litigation - Antitrust
  • Mass Tort Litigation / Class Actions - Plaintiffs
  • Plaintiffs Class Actions
  • Qui Tam Law

Individuals Recognized in The Best Lawyers in America®

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Office Locations

San Francisco, CA
P.O. Box 475847
3749 Buchanan Street
San Francisco, CA 94123
United States
Call our San Francisco, CA location at Get Directions Get directions to our San Francisco, CA location

Management and Personnel

Founder and Managing Partner
Ariana J. Tadler
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