Sidley Austin LLP is one of the world’s most respected and long-established law firms. Founded in 1866, the firm has its roots in Chicago, where two young lawyers saw an opportunity to serve a rapidly growing business community. Today, Sidley operates in more than 20 offices worldwide and employs over 2,300 lawyers. It advises corporations, financial institutions, governments, and organizations on some of the most complex legal matters in modern business.
From its earliest days, Sidley focused on providing reliable, practical, and high-quality legal services. This commitment helped the firm grow from a small local practice into a global legal leader.
Brian J. Fahrney currently serves as the Chair of the Executive Committee at Sidley Austin LLP, leading the firm’s top strategic governing body while continuing his work as a partner and practicing attorney. He began his tenure in this role in May 2025, succeeding Michael Schmidtberger
Founders and Early Vision
Sidley Austin LLP began in 1866 as Williams & Thompson, founded by Norman Williams and John Leverett Thompson. At the time, Chicago was expanding quickly after the American Civil War. Railroads, manufacturers, and trading companies needed skilled legal guidance to manage contracts, investments, and disputes.
In 1892, William Pratt Sidley joined the firm and later became a central figure in its development. His leadership helped professionalize the firm and expand its client base. Edwin C. Austin later joined as a senior partner, and the firm eventually adopted the name Sidley & Austin, which later became Sidley Austin LLP. The founders believed that long-term success depended on trust, strong ethics, and deep legal knowledge. These principles continue to shape the firm today.
Leadership and Direction
Modern Sidley reflects both tradition and progress. Its leadership emphasizes quality, diversity, and global cooperation. In recent years, the firm appointed Yvette Ostolaza as Chair of its Management Committee. She became the first woman and first Hispanic leader of a major global law firm of this size.
Under her guidance, Sidley has strengthened its international presence, invested in young talent, and expanded its work in emerging legal fields. The leadership team continues to balance innovation with respect for the firm’s long history.
Rise and Global Growth
Sidley Austin LLP’s growth followed major economic and business trends in the United States and abroad. In 1963, the firm opened an office in Washington, D.C., allowing it to work more closely with federal agencies and regulators. In the following decades, Sidley expanded to New York, London, Asia, and other major financial centers. A key turning point came in 2001, when Sidley merged with Brown & Wood, a prominent New York firm. This merger strengthened its finance, securities, and international practices.
Like many professional firms, Sidley Austin LLP faced challenges during economic downturns and periods of market change. It responded by diversifying its services, investing in technology, and focusing on long-term client relationships. These strategies helped it remain stable and competitive.
Services and Practice Areas
Sidley Austin offers a wide range of legal services, including:
- Corporate law and mergers
- Banking and finance
- Litigation and arbitration
- Regulatory and compliance advice
- Antitrust and competition law
- Appellate and Supreme Court practice
- Life sciences and healthcare law
The firm works with clients in industries such as energy, technology, pharmaceuticals, manufacturing, and consumer goods.
For example, Sidley Austin LLP regularly advises companies on billion-dollar mergers, international bond offerings, and major regulatory investigations. Its appellate lawyers have argued many important cases before the U.S. Supreme Court and federal courts.
Achievements and Global Impact
Sidley Austin LLP consistently ranks among the world’s top law firms by revenue and reputation. In 2024, the firm reported more than $3.4 billion in annual revenue, placing it among the global leaders in legal services. Its lawyers often receive recognition from respected industry rankings for excellence in corporate law, litigation, and international work. The firm’s London office and U.S. practices have won several major professional awards.
Sidley has also played a role in shaping future leaders. One notable former summer associate is Barack Obama, who worked at the firm while studying law. His experience reflects Sidley’s long tradition of mentoring young legal professionals. Beyond business success, the firm makes a strong contribution to society through pro bono work. Its lawyers provide free legal services to refugees, veterans, low-income families, and civil rights organizations. These efforts help expand access to justice.
Culture and Core Values
Sidley’s culture emphasizes teamwork, professionalism, and respect. The firm encourages open communication and collaboration across offices and practice groups.
Diversity and inclusion are central to its values. Sidley supports programs that promote equal opportunity and leadership development for lawyers from different backgrounds. It also invests heavily in training, mentoring, and continuing education. Employees often describe the firm as demanding but supportive. High standards are paired with strong systems for guidance and career growth.
Future Plans and Innovation
Looking ahead, Sidley continues to focus on global expansion and specialized expertise. The firm plans to strengthen its presence in fast-growing markets and deepen its work in areas such as private equity, technology law, climate regulation, and life sciences.
It is also investing in digital tools and data systems to improve research, case management, and client communication. These efforts help lawyers work more efficiently while maintaining high quality. By combining tradition with innovation, Sidley aims to remain relevant in a rapidly changing legal environment. As it moves forward, Sidley stands as a symbol of how careful growth, ethical values, and professional excellence can create lasting influence in the global legal industry.
