Sidley Austin
| Headquarters | One South Dearborn Chicago, Illinois, U.S. |
|---|---|
| No. of offices | 21 worldwide |
| No. of attorneys | 2,300 |
| Major practice areas | General practice |
| Revenue | $3.4 billion (2024) |
| Profit per equity partner | $5,157,000 (2025) |
| Date founded | 1866 |
| Founder | Norman Williams John Leverett Thompson |
| Company type | Limited liability partnership |
| Website | sidley.com |
Sidley Austin LLP is an American multinational law firm with approximately 2,300 lawyers in 21 offices across the world, including North America, Europe, Asia, and Australia. It was established in 1866 and its headquarters is at One South Dearborn in Chicago's Loop. It is one of the largest law firms in the world in terms of revenue. Among its notable alumni are former U.S. President Barack Obama and current U.S. Vice President JD Vance.