Derek W. Loeser

Derek is a partner in Keller Rohrback’s nationally recognized Complex Litigation Group and a member of the firm’s Executive Committee.

Derek's passion for holding large corporations accountable for wrongdoing has helped recover billions of dollars for consumers, retirees, governments and institutions. He has served in leadership roles in multidistrict litigation and major complex cases across the country.

Derek currently serves as co-lead counsel in In Re: TikTok, Inc, Minor Privacy Litigation, the MDL in which Plaintiffs allege that TikTok unlawfully collects and uses the personal information of children under the age of 13. He also is co-lead counsel in In re Facebook, Inc. Consumer Privacy User Profile Litigation, the MDL litigation against Facebook stemming from the Facebook Cambridge Analytica scandal. In the case, after years of hard-fought litigation, he and the team achieved a historic $725 million settlement, the largest amount paid to date to resolve a privacy-based class action. 

Other notable class action cases in which Derek serves as lead or co-lead counsel include: In re Wells Fargo COVID Forbearance Litigation, a consumer class action against Wells Fargo for putting mortgage customers into unauthorized loan forbearances. On February 15, 2025, the court granted final approval of a $185 million settlement for a class of over 200,000 borrowers;  Jabbari, et al. v. Wells Fargo & Company and Wells Fargo Bank, N.A., the consumer class action arising out of Wells Fargo’s notorious unauthorized account scandal. In this case, Derek and the Keller Rohrback team achieved a $142 million settlement requiring the bank to refund all improper fees and provide first-of-its kind credit damage reimbursement, among other relief, to Wells Fargo customers. 

Derek also served as lead counsel in multi-billion dollar mortgage-backed securities cases on behalf of the Federal Home Loan Banks of Chicago, Indianapolis and Boston; ERISA class cases on behalf of employees whose retirement savings were decimated by corporate fraud and abuse on the part of Enron, WorldCom, Countrywide, and Washington Mutual, among others. He has also litigated fraud, RICO, and antitrust cases against drug manufacturers, pharmacy benefit managers, and insurance companies for conspiring to drive up the cost of life-saving medications such as insulin.

In addition to his class action work, Derek helps manage the Keller Rohrback team representing state and local government entities in a number of matters involving significant public health crises. For example, Derek leads the Keller Rohrback team litigating government cases against opioid manufacturers and distributors in The National Prescription Opioid Litigation. In the Opioid MDL, Derek serves on the Expert and Law & Briefing Committees and led the litigation against a major opioid manufacturer, Mallinckrodt. He also represented school districts and counties in litigation against the e-cigarette company, JUUL, for targeting and addicting youth. These cases are quintessential examples of the type of litigation Derek and the Keller Rohrback team passionately pursue – corporate fraud and malfeasance causing serious harm to the public.

Many of Derek’s cases have required coordinating with state and federal agencies involved in litigation that parallels cases pursued by Keller Rohrback, including state attorneys general, the Department of Justice, and the Department of Labor. In addition, Derek has extensive experience negotiating complex, multi-party settlements, and coordinating with the many parties and counsel necessary to accomplish this. He is frequently asked to speak at national conferences about class actions, public health litigation, ERISA, and other complex litigation topics.

Derek has been included on the Super Lawyers® "Top 100: Washington Super Lawyers" list from 2022 through 2026, and he was recognized by Law360 as a "Titan of the Plaintiffs Bar" in 2024, Forbes inaugural list of America’s Top 200 Lawyers in 2024, Lawdragon 500 Leading Lawyers in America 2018, 2022-2027, along with a variety of other prestigious recognitions.

Before joining Keller Rohrback, Derek served as a law clerk for the Honorable Michael R. Hogan, U.S. District Court for the District of Oregon. He was also a trial attorney in the Employment Litigation Section of the Civil Rights Division of the U.S. Department of Justice in Washington, D.C. where he prosecuted discrimination cases on behalf of the United States.