Daniel Horowitz

Daniel M. Horowitz, partner at litigation boutique Holwell Shuster & Goldberg LLP, has been instrumental to the firm’s success in a number of its most high-profile cases. Daniel is a generalist litigator who has brought his expertise to bear in all forms of large-scale commercial disputes, including in antitrust and insurance defense cases.

He has been at the center of industry-defining litigation for a major insurer with respect to two public health crises, the opioid epidemic and youth social media addiction, including claims brought by major manufacturers, the nation’s largest drug distributors, and its largest pharmacy chains seeking insurance coverage for opioid abatement lawsuits, and separately by Meta concerning social media addiction. Daniel and the HSG team have secured multiple summary judgment, forum, and appellate victories for a major insurer, including in the Ninth Circuit and the Delaware Supreme Court.

Daniel is a key member of the HSG team representing video game distribution company Valve Corporation in defense of mass arbitration brought under the antitrust laws. He was also a key member of the team representing Visa Inc. in its defense against claims brought by several of the country’s largest retailers challenging the rules at the foundation of the modern payments industry.

Daniel has also defended the Public Campaign Financing and Election Commission of the State of New York against a challenge to its authority to issue recommendations to establish a public campaign financing program in New York State, and the Governor of the State of New York in a challenge to a statute related to salaries for legislators and executive-branch employees.

Daniel is also a leader in the firm’s pro bono efforts, and his contributions have helped secure HSG’s recognition from Law360 as the number one boutique in the nation for pro bono work and Benchmark Litigation’s Pro Bono Firm of the Year. His recent representations include achieving the rare result of having a removal order vacated after his client’s deportation and then coordinating the client’s return to the United States. He has also represented numerous prisoners in civil rights litigation, including a favorable settlement involving inadequate dental care at Sing Sing prison.

Following law school, Daniel served as a judicial law clerk to the Hon. Priscilla Owen (now Richman) of the U.S. Court of Appeals for the Fifth Circuit and the Hon. Frederic Block of the U.S. District Court for the Eastern District of New York.

He has been named to Benchmark Litigation’s 40 & Under List (since 2024), Law360’s Rising Stars (2026), and the Lawdragon 500 X – The Next Generation list (2024, 2025, 2026). In 2025, Daniel received Profiles in Leadership Journal’s Legal Leadership Award.