# Sidley Austin
**Sidley Austin LLP** is a law firm with a worldwide presence that traces its origins to Chicago in 1866, the year Norman Williams and John Leverett Thompson joined forces to start a practice, sharing an office in the Marine Bank building where Lake and LaSalle Streets intersect[1](https://www.sidley.com/en/newslanding/newsannouncements/2026/10/sidley-celebrates-160-years). The firm counts approximately 2,300 lawyers and more than 650 partners working from 22 offices, including a new Miami office, in commercial and financial centers worldwide[2](https://chambers.com/law-firm/simpson-thacher-bartlett-llp-global-2%3A3692), and reports US$3.1 billion in revenue in its Chambers profile[2](https://chambers.com/law-firm/simpson-thacher-bartlett-llp-global-2%3A3692).
| Key fact | Detail |
|---|---|
| Founded | 1866, Chicago, by Norman Williams and John Leverett Thompson[1](https://www.sidley.com/en/newslanding/newsannouncements/2026/10/sidley-celebrates-160-years) |
| Scale | About 2,300 lawyers, over 650 partners, 22 offices worldwide[2](https://chambers.com/law-firm/simpson-thacher-bartlett-llp-global-2%3A3692) |
| Revenue | US$3.1 billion per its Chambers Global 2026 profile; $3.738 billion (+8.68%) in the AmLaw 100 2026 revenue table[2](https://chambers.com/law-firm/simpson-thacher-bartlett-llp-global-2%3A3692) • [3](https://sartoriglobal.com/insights/market/am-law-100-2026-table/) |
| Leadership | Brian J. Fahrney chairs the Executive Committee; Yvette Ostolaza chairs the Management Committee[2](https://chambers.com/law-firm/simpson-thacher-bartlett-llp-global-2%3A3692) |
| Pro bono | More than 160,000 hours annually firmwide, with over 1,600 lawyers participating at an average of 70 hours each[4](https://www.sidley.com/en/probonolanding) |
| Recognition | 153 practice rankings and 377 lawyer rankings in Chambers USA 2026, including Band 1 in 31 practice areas[5](https://www.sidley.com/en/newslanding/newsachievements/2026/06/sidley-highly-ranked-in-chambers-usa-2026) |
| New partners | 52 lawyers elected to the partnership in June 2026[6](https://www.sidley.com/en/newslanding/newpressreleases/2026/06/sidley-elects-new-partnership-class-of-52) |
## Origins and growth
The firm traces its Chicago roots to 1866, and it celebrated the 160th anniversary of the founding meeting in October 2026[1](https://www.sidley.com/en/newslanding/newsannouncements/2026/10/sidley-celebrates-160-years). The Chicago office remains one of the firm's largest, with nearly 500 lawyers working on high-stakes litigation, complex transactions, and regulatory matters[7](https://www.sidley.com/en/locations/offices/chicago).
Expansion beyond the United States began with London, where the firm gained what its Legal 500 profile calls a significant advantage in 1994 by offering [English law](https://www.edgepedia.org/english-law) advice alongside US legal advice; its London clients include leading financial institutions and FTSE 100 and [Fortune 500](https://www.edgepedia.org/fortune-500) companies[8](https://www.legal500.com/firms/50912-sidley-austin-llp/global/about). Growth continues through lateral hiring: in July 2026 the firm added capital markets partner Andrew Baker from [Latham & Watkins](https://www.edgepedia.org/latham-and-watkins), following several other New York partner additions that year in capital markets, tax, banking and fintech, global finance, antitrust, and investment funds[9](https://www.sidley.com/en/newslanding/newpressreleases/2026/07/sidley-continues-new-york-growth-with-capital-markets-partner-andrew-baker). In the same month Sidley recruited a five-partner finance group from Clifford Chance in New York and Washington, led by Lee Askenazi, who had co-led Clifford Chance's financial markets team[10](https://news.bloombergtax.com/financial-accounting/sidley-lands-five-partner-finance-group-from-clifford-chance).
## Practice and recognition
Sidley describes itself as an elite global firm advising on complex transactional, restructuring, crisis management, investigation, regulatory, and litigation matters[11](https://www.sidley.com/en/about-sidley). Its self-described BUILT TO WIN model prioritizes investment in data, technology, knowledge management, and business support[12](https://www.sidley.com/en/insights/resources/built-to-win).
Third-party rankings give a measure of the firm's breadth. In Chambers USA 2026 it received 153 practice rankings and 377 lawyer rankings, with Band 1 status in 31 practice areas and 69 Band 1 lawyer rankings[5](https://www.sidley.com/en/newslanding/newsachievements/2026/06/sidley-highly-ranked-in-chambers-usa-2026). Legal 500 recognized the firm with 63 practice area rankings in the United States in 2026[13](https://www.sidley.com/en/newslanding/newsachievements/2026/06/sidley-recognized-in-legal-500-united-states-2026). Individual practice depth is visible in appellate work: partner Carter Phillips had argued 87 cases before the U.S. Supreme Court as of a 2019 report[14](https://time.com/5692448/hrc-challenge-trump-lgbt/).
## Pro bono and community work
Pro bono service is organized around firmwide initiatives: the Capital Litigation Project, which provides representation to people incarcerated on Alabama's death row; the Political Asylum and Immigrants' Rights Project; the Veterans Advocacy Project; the Constitutional Rights and Civil Liberties Project; the Pro Bono Project for the Arts; and the Emerging Enterprises Pro Bono Program, launched in 2012 to provide free legal support to eligible small- and medium-size organizations[4](https://www.sidley.com/en/probonolanding). In 2025 the firm reported more than 160,000 firmwide pro bono hours, with over 1,600 lawyers involved at an average of 70 hours per lawyer[4](https://www.sidley.com/en/probonolanding). Its veterans work included more than 12,000 pro bono hours in 2024 alone[15](https://news.bloomberglaw.com/social-justice/pro-bono-innovators-2025-honoree-sidley-austin).
The Chicago office contributes more than 45,000 pro bono hours annually and serves more than 200 cultural, academic, and civic organizations[7](https://www.sidley.com/en/locations/offices/chicago). Sidley became the first law firm in Chicago to adopt a public school when, in 1984, it entered a partnership with Kanoon Magnet Elementary School, an arrangement the firm calls the longest-standing one of its sort in the city.[7](https://www.sidley.com/en/locations/offices/chicago)
## Recent developments
Sidley's partnership class elected in June 2026 numbered 52, up from 29 in 2025 and 38 in 2024[6](https://www.sidley.com/en/newslanding/newpressreleases/2026/06/sidley-elects-new-partnership-class-of-52) • [3](https://sartoriglobal.com/insights/market/am-law-100-2026-table/). In the AmLaw 100 2026 revenue table the firm's gross revenue was $3.738 billion, up 8.68 percent[3](https://sartoriglobal.com/insights/market/am-law-100-2026-table/).
## References
1. [Sidley Celebrates 160 Years, Sidley Austin LLP](https://www.sidley.com/en/newslanding/newsannouncements/2026/10/sidley-celebrates-160-years)
2. [Sidley Austin LLP, Chambers Global 2026 profile](https://chambers.com/law-firm/simpson-thacher-bartlett-llp-global-2%3A3692)
3. [Am Law 100 2026: Revenue, PEP Table, Sartori & Partners](https://sartoriglobal.com/insights/market/am-law-100-2026-table/)
4. [Pro Bono, Sidley Austin LLP](https://www.sidley.com/en/probonolanding)
5. [Sidley Highly Ranked in Chambers USA 2026, Sidley Austin LLP](https://www.sidley.com/en/newslanding/newsachievements/2026/06/sidley-highly-ranked-in-chambers-usa-2026)
6. [Sidley Elects New Partnership Class of 52, Sidley Austin LLP](https://www.sidley.com/en/newslanding/newpressreleases/2026/06/sidley-elects-new-partnership-class-of-52)
7. [Chicago | Locations, Sidley Austin LLP](https://www.sidley.com/en/locations/offices/chicago)
8. [Sidley Austin LLP, Legal 500 Global profile: About](https://www.legal500.com/firms/50912-sidley-austin-llp/global/about)
9. [Sidley Continues New York Growth With Capital Markets Partner Andrew Baker, Sidley Austin LLP](https://www.sidley.com/en/newslanding/newpressreleases/2026/07/sidley-continues-new-york-growth-with-capital-markets-partner-andrew-baker)
10. [Sidley Lands Five-Partner Finance Group From Clifford Chance, Bloomberg Tax](https://news.bloombergtax.com/financial-accounting/sidley-lands-five-partner-finance-group-from-clifford-chance)
11. [About Sidley, Sidley Austin LLP](https://www.sidley.com/en/about-sidley)
12. [Built to Win®, Sidley Austin LLP](https://www.sidley.com/en/insights/resources/built-to-win)
13. [Sidley Recognized in Legal 500 United States 2026, Sidley Austin LLP](https://www.sidley.com/en/newslanding/newsachievements/2026/06/sidley-recognized-in-legal-500-united-states-2026)
14. [Human Rights Campaign Partners With 6 Prestigious U.S. Law Firms to Challenge Trump on LGBT Rights, Time](https://time.com/5692448/hrc-challenge-trump-lgbt/)
15. [Pro Bono Innovators 2025 Honoree Sidley Austin, Bloomberg Law](https://news.bloomberglaw.com/social-justice/pro-bono-innovators-2025-honoree-sidley-austin)
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*Topic: Encyclopedia › Society and history › Law and justice › Commercial, financial, and employment law › Commercial legal practice and dispute resolution*
*Initially written Sep 17, 2026 · Reviewed: Sep 17, 2026; Oct 25, 2026 · Edited: Oct 15, 2026; Oct 25, 2026 · Last review: Oct 25, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license