Sidley Austin
| Company type | Limited liability partnership |
|---|---|
| Industry | Legal services |
| Founded | 1866 |
| Founder | Norman Williams, John L. Thompson |
| Headquarters | Chicago , United States |
Area served | Worldwide |
| Products | Legal services |
Number of employees | 2,300 lawyers (2025) |
| Website | www |
Sidley Austin LLP is a multinational law firm headquartered in the United States, employing roughly 2,300 lawyers across 21 offices worldwide. Established in 1866, its main office is situated at One South Dearborn in Chicago's Loop district. The firm ranks among the top global law firms based on revenue.
1866–1900s: Chicago Foundations
The firm originated in Chicago in 1866 when Norman Williams and John L. Thompson founded Williams & Thompson. William Pratt Sidley became a partner in 1892, prompting a name change to Holt, Wheeler & Sidley by 1900. Edwin C. Austin joined the partnership in 1914.
Its early clientele featured prominent companies such as the Pullman Company, Western Electric, and Illinois Steel.
20th Century: Growth and Mergers
In 1963, the firm launched its Washington, D.C. branch under the leadership of former Postmaster General J. Edward Day, attracting initial clients like the Advertising Mail Marketing Association.
The 1972 merger with Chicago-based Leibman, Williams, Bennett, Baird & Minow expanded Sidley Austin’s footprint to London, Los Angeles, Singapore, and New York. Following this merger, Day resigned and pursued legal action alleging breaches of fiduciary duty; however, the lawsuit was dismissed with prejudice.
In 1985, U.S. Solicitor General Rex E. Lee established Sidley Austin’s Appellate Practice Group, which has represented clients before all appellate courts including the U.S. Supreme Court. After Lee’s passing, Carter Phillips took over leadership and has argued more cases at the Supreme Court than any other private attorney.
In 1991, Sidley & Austin resolved legal malpractice claims related to its representation of Lincoln Savings and Loan during the Savings & Loan Crisis by agreeing to a $7.5 million settlement.
21st Century Developments
Sidley Austin merged with New York-based Brown & Wood in 2001, a firm recognized for its expertise in securities, structured finance, and securitization practices with offices in Washington D.C., San Francisco, Los Angeles, London, Beijing, and Hong Kong. The merged entity initially planned to occupy space in the World Trade Center but relocated to Midtown Manhattan’s Axa Equitable Center following the September 11 attacks.
In 2007, Sidley Austin settled IRS allegations concerning fraudulent tax shelter schemes by paying $39 million; prior settlements included $54 million paid jointly by Sidley and KPMG to investors affected by these shelters.
In 2019, Sidley successfully represented Airbus in a World Trade Organization dispute that enabled the European Union to implement retaliatory measures against U.S. subsidies granted to Boeing. By that year, Sidley had participated in approximately half of the last 550 WTO dispute cases.
The firm currently operates offices in 21 cities globally, having added Miami in 2022 and San Diego scheduled for opening in 2024.
Advocacy for Chinese Technology Corporations
Reports from Politico in August 2019 revealed that Chinese tech giant Huawei engaged Sidley Austin for lobbying efforts following U.S. governmental restrictions on its business dealings. These efforts concentrated on matters related to trade policies, sanctions compliance, export controls, and national security concerns.
In October 2022, investigations by Reuters and Politico disclosed that Sidley Austin amended its registration under the Foreign Agents Registration Act to act as lobbyist for Hikvision USA, a California-based subsidiary of Chinese surveillance company Hikvision, at the request of the U.S. Department of Justice. The firm reported receiving around $7.4 million in fees since 2018 and was initially registered under the Lobbying Disclosure Act of 1995.
Early in 2024, after other agencies ceased representation, Sidley Austin was retained by DJI Technologies, reflecting intensified lobbying activities by Chinese technology companies facing increased regulatory oversight from U.S. authorities.
Rankings and recognition
In 2025, Sidley Austin is positioned as the sixth-largest law firm worldwide based on revenue, employing around 2,300 attorneys and generating annual revenues surpassing $3.4 billion. The firm stands out as one of the top-paying employers in the United States, underscoring its robust financial health and effective strategies for retaining top talent.
BTI Consulting Group honored Sidley in 2023 by including it on its Client Service A-Team, a distinction shared by only three firms that have appeared in every edition since 2001. Other notable recognitions include the American Bar Association’s 2019 Champions for Disability Inclusion Award and being a finalist for The American Lawyer's 2019 Litigation Department of the Year.
Sidley’s International Trade Group was recognized as 2019 Group of the Year by Law360 and has consecutively received the "Law Firm of the Year" award in Trade & Customs from Who's Who Legal for 15 years. The firm’s appellate and U.S. Supreme Court practice has been acknowledged in prominent legal outlets such as USA Today, BusinessWeek, and The American Lawyer.
In 2020, Sidley earned several "Firm of the Year" awards from China Business Law Journal across multiple sectors including Capital Markets (Overseas), Corporate Compliance, Healthcare, Pharma and Life Sciences, and Real Estate. Additionally, in 2018, it was awarded Competition & Regulatory Team of the Year at The Lawyer Awards held in London.
Pro bono work
Sidley Austin partner George Fatheree played a pivotal role in providing extensive pro bono legal assistance to the descendants of Willa and Charles Bruce to recover beachfront property confiscated by Los Angeles officials during the 1920s. Known as Bruce's Beach, this land had been appropriated for public use before being sold to private buyers. Following over 1,000 hours dedicated to pro bono efforts, ownership was formally returned to Marcus and Derrick Bruce, great-grandsons of the original owners, on July 20, 2022.
Associates and alumni
- James M. Cole, partner; former deputy attorney general and author of the Cole Memorandum
- J. Edward Day, former postmaster general
- George Deukmejian, former governor of California
- Joseph D. Kearney, dean of Marquette University Law School
- Mike Lee, U.S. senator from Utah
- Rex E. Lee, former solicitor general and tenth president of Brigham Young University
- Chris Lu, former U.S. deputy secretary of labor and ambassador to the United Nations for Management and Reform
- Victor Marrero, senior judge at the U.S. District Court for the Southern District of New York
- Newton N. Minow, former chairperson of the Federal Communications Commission
- Barack Obama, former president of the United States (summer associate)
- Michelle Obama, former first lady of the United States
- Peter Roskam, partner; ex-U.S. representative for Illinois's 6th congressional district
- Andy Strenio, former member of the Federal Trade Commission
- David S. Tatel, judge on the U.S. Court of Appeals for the District of Columbia Circuit
- JD Vance, U.S. senator from Ohio and vice president of the United States
- John D. Zeglis, former CEO of AT&T Wireless