Wilson Sonsini Goodrich & Rosati

The firm's headquarters are on Page Mill Road in Palo Alto, California, as a part of the Stanford Research Park.

In total, Wilson Sonsini has offices in ten major cities in the U.S., including Austin, Texas; Boston, Massachusetts; Los Angeles, California; New York City; Palo Alto, California; San Diego, California; San Francisco, California; Seattle, Washington; Washington, D.C.; and Wilmington, Delaware. Outside of the United States, it has offices in Hong Kong; Beijing and Shanghai, China; Brussels, Belgium; and London, England.

Wilson Sonsini was founded in 1961 as McCloskey, Wilson, Mosher & Martin in Palo Alto, California, with attorney Pete McCloskey and attorney John Arnot Wilson being two of the first named partners. Wilson was a graduate of Princeton University and Yale Law School's class of 1941, which included Supreme Court jurists Byron White and Potter Stewart as well as former President Gerald Ford.[35] Since its launch, the firm concentrated on the representation of emerging technology companies and venture capitalists. For example, in 1969, the firm helped form Mayfield Fund, one of the first major venture capital firms. In 1970, John B. Goodrich joined the firm. Larry Sonsini and Mario Rosati joined in 1966 and 1971, respectively. In 1978, the firm takes on the name it has had since: Wilson Sonsini Goodrich & Rosati, PC. The firm recently started to use the shortened name, "Wilson Sonsini" in conjunction with launching a new firm website, on November 6, 2019.

In 1980, Wilson Sonsini represented Apple Inc. in its much-publicized IPO. The firm was also involved in representing companies in the semiconductor industry, like LSI Logic, Altera, Cirrus Logic, Lattice Semiconductor, and Cypress Semiconductor. These companies were among those that helped Silicon Valley earn its name.

For many years, Wilson Sonsini had only one office, in Palo Alto. In late 1998, the firm opened its first national office, in Kirkland, Washington, led by partner Patrick Schultheis. Within the next few years, the firm opened offices in Austin, Texas, San Francisco, Northern Virginia, New York, Salt Lake City, and San Diego.

Like other law firms representing start-up technology companies, Wilson Sonsini accepted equity in its clients as a form of payment in return for deferral of fees, and also passed on stakes in its investment fund to associates and staff members as a means of retaining employees.[36]

In 1994, Wilson Sonsini represented Netscape Communications in its IPO, in addition to representing several other companies that, like Netscape, were tied to the start of the Internet Age, including Infoseek, USWeb/CKS, and Inktomi. Wilson Sonsini also began to lead the nation in the number of issuer IPO transactions, completing 37 IPOs in 1995 and 44 IPOs in 1997.

In 1999, when VA Linux went public, the firm reaped $24.5 million as the value of the 100,000 shares that the firm held ballooned in value. Other IPOs that enriched the firm because of its equity stake were those of Ask Jeeves, Google, and online grocer Webvan. With the downturn in the dotcom economy, however, Wilson Sonsini had to make a number of adjustments; 100 support staff and 60 associates were laid off—about 10% of its attorneys. Better times eventually returned. For example, in 2004 when the firm advised Google on its $2.7 billion IPO. In 2005, Wilson Sonsini launched an office in China and boosted its New York office. In 2006 the firm relocated its Northern Virginia lawyers to Washington, D.C., to be closer to government regulators.

In 2016, Wilson Sonsini represented long-time client LinkedIn in their $26.2 billion acquisition by Microsoft, which represented Microsoft's largest ever acquisition.[37]

In addition to numerous professors and partners, both at Wilson Sonsini and other firms, some of the more notable current and former Wilson Sonsini attorneys include:

• Michael Arrington, Founder, TechCrunch
• Steven E. Bochner, Board of Directors, Federal Reserve Bank of San Francisco
• William B. Chandler, III, judge, Delaware Superior Court; Chancellor, Delaware Court of Chancery (1989–2007)
• Peter Detkin, Managing Partner at Intellectual Ventures
• David Drummond, Chief Legal Officer and Senior Vice President at Google
• Mark Farrell, Supervisor, San Francisco Board of Supervisors (2011 –)
• Richard Frenkel, former Director of Intellectual Property at Cisco
• Vijaya Gadde, current General Counsel and Legal Director at Twitter
• Chris Kelly, first General Counsel of Facebook, Democratic Candidate for Attorney General of California
• Alex Macgillivray, former General Counsel at Twitter; Deputy Chief Technology Officer of the United States (2014 -)
• Ro Khanna, Congressman, United States House of Representatives (2017 -); former Deputy Assistant Secretary, United States Department of Commerce;
• Lucy H. Koh, judge, United States District Court for the Northern District of California (2010 -)
• Katharine (Katie) Martin, Partner and Chair of the Board of Directors, Wilson Sonsini Goodrich & Rosati
• Pete McCloskey, Congressman, United States House of Representatives (1967–83)
• Tamika Montgomery-Reeves, Delaware Supreme Court Justice (2019 -)[38]
• John Roos, former CEO of Wilson Sonsini; United States Ambassador to Japan (2009–13)
• Larry Sonsini, Senior Partner and Founder, "Godfather" of Silicon Valley Law[39]
• Joshua D. Wright, Commissioner, Federal Trade Commission (2013 -)