Wilson Sonsini Goodrich & Rosati

In 1961, Pete McCloskey, John Wilson, and Roger Mosher opened a small office on Welch Road in Palo Alto, founding the law firm McCloskey, Wilson & Mosher, about a decade before the term “Silicon Valley” came into wide use. Wilson later wrote in his recollections that the firm was formed to carry out a “full service plan,” which included a passion for “interesting work,” a resolve to stay in close touch with clients to understand their business objectives, a willingness to “take some risks” on clients the firm believed in, teamwork, and a commitment to diversity.⁠[1][1][1][1]

Wilson, one of the founders, had earlier worked as a lawyer for the U.S. Atomic Energy Commission and then at a firm in Cleveland, Ohio, before moving to California by 1957 to work in-house for Hiller Aircraft.⁠[2][2]

In 1966, Lawrence W. (Larry) Sonsini, a graduate of the UC Berkeley School of Law, joined the firm as its first associate; he later became its chairman and chief executive.⁠[2][2][1]

Six years after the firm’s founding, McCloskey left to represent California in the U.S. Congress.⁠[1]

In 1968, the firm handled its first initial public offering (IPO), for Behavioral Research Laboratories. By 1969, Wilson had also co-founded the venture capital firm Mayfield Fund, which went on to become a prominent venture firm.⁠[2][2]

In 1970, John B. Goodrich joined to start a tax practice, and the following year Mario M. Rosati joined to build a trusts and estates practice; both later became name partners. In 1970, Sonsini handled his first IPO, the listing of Coherent Radiation.⁠[2][2]

In 1973, the firm was renamed Wilson, Mosher & Sonsini.⁠[1]

In 1975, the firm handled the IPO of ROLM, a computer maker that later moved into telecommunications and was one of the firm’s first key clients.⁠[2][2]

In 1978, Mosher left to form a litigation boutique, taking at least three of the firm’s 25 lawyers with him; the firm was then renamed Wilson Sonsini Goodrich & Rosati. Facing the split, Wilson and Sonsini met in Wilson’s ninth-floor office at Palo Alto Square on Page Mill Road to decide their next step; Sonsini argued for continuing to tailor the firm to the technology industry and recommended creating a litigation group and adding a securities specialist from the U.S. Securities and Exchange Commission (SEC).⁠[2][1][2][2]

Steven E. Bochner (chief executive as of 2011) recalled that the partners realized that unless they scaled their expertise quickly, they would not keep up with fast-growing, increasingly sophisticated clients and would lose ground to other firms.⁠[2]

By 1979 the firm had hired Jeffrey D. Saper from the SEC (he later became vice chairman); by 1984 it had brought in Bruce G. Vanyo from the litigation boutique McCutchen, Doyle, BrownBrown UniversityBrown University is a private nonprofit research university in Providence, Rhode Island, and a member of the Ivy League. Chartered by Rhode Island's colonial legislature in 1764, it is known for its undergraduate Open Curriculum, which has no common required core. Christina H. Paxson, president since July 2012, announced on August 3, 2026, that the 2026–27 academic year would be her last in office. As of October 1, 2026, the search for Brown's 20th president remained underway.Open the full entry & Enersen to start its litigation practice together with former assistant U.S. attorney Steven M. Schatz; and in 1986 Boris Feldman became the firm’s first securities litigator. By the mid-1980s the firm had made key hires in litigation, particularly securities litigation, added environmental law experts, and strengthened its corporate department; in the 1990s and 2000s it expanded further into intellectual property, life sciences, clean technology, and antitrust.⁠[2][2][2][2][2]

In 1980, the firm served as counsel on the IPO of Apple Computer.⁠[2][3]

In 1993, Craig W. Johnson, the firm’s eleventh lawyer, left with about $8 million in business to found Venture Law Group, a corporate law boutique for startups; his wish to focus more on startups and to open an office on Sand Hill Road alongside the venture capitalists was not shared by his old firm.⁠[2][2]

After several moves and expansions, the firm settled its headquarters at 650 Page Mill Road in Palo Alto in 1994.⁠[1]

In 1995, the firm served as counsel on the IPO of Netscape Communications.⁠[2]

In 1998, the firm opened its first office outside California, in Kirkland, Washington (relocated to Seattle in 2004), followed by offices in Austin (1999), San Francisco (1999), the Washington, D.C., area (2000), New York (2001), and San Diego (2004); a Salt Lake City office opened in 2001 was closed in 2007. The expansion grew out of initiatives by young lawyers: then-partner Patrick J. Schultheis wanted to move to Seattle and then-associate Paul R. Tobias hoped to return to his home state of Texas, and each wrote a business plan for winning technology clients in those markets that the partnership adopted.⁠[1][2][2][2]

In 1999, the firm served as counsel on the IPO of Agilent Technologies. The same year, founder John Wilson died; he remained a vital part of the firm until his death.⁠[2][1]

On April 29, 2004, Google filed its IPO registration statement (Form S-1) with the SEC, listing Larry Sonsini and David J. Segre as company counsel, with Wilson Sonsini passing upon the validity of the Class A common stock offered. According to the registration statement, certain members of Wilson Sonsini and investment partnerships made up of its members held less than 0.1% of Google’s Class B common stock; Google’s then general counsel, David C. Drummond, had been a partner at the firm.⁠[4][4][4][4][4]

In 2005, Sonsini handed the chief executive role to John V. Roos while retaining the chairmanship; Roos became the firm’s second chief executive. Market speculation about whether the firm could survive without Sonsini at its head had led it to formalize a succession plan that made room for leaders such as Roos and Bochner.⁠[2][2]

In 2007, the firm opened its first international office, in Shanghai, China, followed by an office in Hong Kong in 2010.⁠[1]

In 2010, the firm served as counsel on the IPO of Tesla Motors.⁠[2]

On February 1, 2011, the firm announced that it was celebrating its 50th anniversary; then-chairman Sonsini said the firm had more than 600 attorneys and a client base of thousands of growth enterprises. As of May 2011, the firm had roughly 600 lawyers in nine offices, and its profits per equity partner in 2010 were $1.5 million; its chief executive was Steven E. Bochner, and Jeffrey D. Saper was vice chairman.⁠[1][1][1][2][2][2][2]

At the time the firm had long focused on technology clients and did not handle insurance matters, mass torts, or public finance; two Silicon Valley firms, Fenwick & West and Cooley, had replicated its business model and were its main local competitors.⁠[2][2]

In 2012, Douglas Clark, who had led the firm’s litigation department for several years, became managing partner. The firm has said that its annual revenue grew from $549 million in 2012 to $1.4 billion in 2025.⁠[3][3][3]

In November 2013, firm partner Katharine Martin helped take Twitter public.⁠[5][5]

In 2016, the firm represented LinkedInLinkedInLinkedIn is a social networking platform for professionals. It was founded in 2002 by Reid Hoffman and others, launched in 2003, and listed on the New York Stock Exchange in 2011; after Microsoft acquired it for approximately $26.2 billion in 2016, it became a wholly owned Microsoft subsidiary. Its revenue comes from membership subscriptions, advertising, and recruitment solutions.Open the full entry in its acquisition by MicrosoftMicrosoftMicrosoft is a technology company founded by Bill Gates and Paul Allen in 1975 and headquartered in Redmond, Washington, with businesses spanning Windows, Microsoft 365, Azure, enterprise software, artificial intelligence, gaming and devices.Open the full entry for about $26 billion.⁠[3]

Since 2022 the firm has provided legal services to the AI company AnthropicAnthropicAnthropic is an artificial intelligence research and product company founded in 2021 that develops the Claude models, assistant, and tools such as Claude Code, and operates as a public benefit corporation. Dario Amodei and Daniela Amodei are its co-founders, and its research covers model safety, interpretability, and steerability.Open the full entry, advising on its structure as a public benefit corporation and on investments from Amazon.⁠[3]

On April 25, 2022, Twitter agreed to be sold to an entity owned by Elon Musk and taken private at $54.20 per share, a deal valued at about $44 billion; Wilson Sonsini served as Twitter’s counsel, with a team of roughly 30 lawyers led by firm board chair Katharine Martin, while Simpson Thacher advised Twitter’s board. The firm’s lawyers on the deal came from finance, corporate, technology transactions, privacy, regulatory, tax, and litigation practices.⁠[5][5][3][5][5][5]

On December 3, 2025, the firm announced that managing partner Clark would step down in August 2026 and move into a senior advisory role, to be succeeded as co-managing partners by litigation department head Caz Hashemi and New York capital markets partner Megan Baier. Hashemi, based in Palo Alto, joined the firm from the SEC in 2000 and has served on its board of directors; Baier, based in New York, joined from Ropes & Gray in 2014 and became a partner in 2017.⁠[3][3][3][3][3]

As of December 2025, the firm had more than 1,000 lawyers. That year its lawyers advised fintech company Chime, cybersecurity company Netskope, and Ascentage Pharma on their IPOs, and it was advising Anthropic in the early stages of an initial public offering; meanwhile, larger law firms were building out their emerging companies and venture capital practices, and firms such as Paul Hastings and Orrick hired away several Wilson Sonsini partners.⁠[3][3][3][3][3][3]

Wilson Sonsini Goodrich & Rosati: Official website: https://www.wsgr.com/ (opens in a new window).⁠[1]