For more than four decades, Fenwick & West LLP has helped some of the world’s most recognized companies become, and remain, market leaders. From emerging enterprises to large public corporations, our clients are leaders in the technology, life sciences and cleantech sectors and are fundamentally changing the world through rapid innovation.  MORE >

Fenwick & West was founded in 1972 in the heart of Silicon Valley—before “Silicon Valley” existed—by four visionary lawyers who left a top-tier New York law firm to pursue their shared belief that technology would revolutionize the business world and to pioneer the legal work for those technological innovations. In order to be most effective, they decided they needed to move to a location close to primary research and technology development. These four attorneys opened their first office in downtown Palo Alto, and Fenwick became one of the first technology law firms in the world.  MORE >

From our founding in 1972, Fenwick has been committed to promoting diversity and inclusion both within our firm and throughout the legal profession. For almost four decades, the firm has actively promoted an open and inclusive work environment and committed significant resources towards improving our diversity efforts at every level.  MORE >

FLEX by Fenwick is the only service created by an AmLaw 100 firm that provides flexible and cost-effective solutions for interim in-house legal needs to high-growth companies.  MORE >

Fenwick & West handles significant cross-border legal and business issues for a wide range of technology and life sciences who operate internationally..  MORE >

At Fenwick, we are proud of our commitment to the community and to our culture of making a difference in the lives of individuals and organizations in the communities where we live and work. We recognize that providing legal services is not only an essential part of our professional responsibility, but also an excellent opportunity for our attorneys to gain valuable practical experience, learn new areas of the law and contribute to the community.  MORE >

Year after year, Fenwick & West is honored for excellence in the legal profession. Many of our attorneys are recognized as leaders in their respective fields, and our Corporate, Tax, Litigation and Intellectual Property Practice Groups consistently receive top national and international rankings, including:

  • Named Technology Group of the Year by Law360
  • Ranked #1 in the Americas for number of technology deals in 2015 by Mergermarket
  • Nearly 20 percent of Fenwick partners are ranked by Chambers
  • Consistently ranked among the top 10 law firms in the U.S. for diversity
  • Recognized as having top mentoring and pro bono programs by Euromoney


We take sustainability very seriously at Fenwick. Like many of our clients, we are adopting policies that reduce consumption and waste, and improve efficiency. By using technologies developed by a number of our cleantech clients, we are at the forefront of implementing sustainable policies and practices that minimize environmental impact. In fact, Fenwick has earned recognition in several areas as one of the top US law firms for implementing sustainable business practices.  MORE >

At Fenwick, we have a passion for excellence and innovation that mirrors our client base. Our firm is making revolutionary changes to the practice of law through substantial investments in proprietary technology tools and processes—allowing us to deliver best-in-class legal services more effectively.   MORE >

Mountain View Office
Silicon Valley Center
801 California Street
Mountain View, CA 94041

San Francisco Office
555 California Street
12th Floor
San Francisco, CA 94104

Seattle Office
1191 Second Avenue
10th Floor
Seattle, WA 98101

New York Office
1211 Avenue of the Americas
32nd Floor
New York, NY 10036

Shanghai Office
Unit 908, 9/F, Kerry Parkside Office
No. 1155 Fang Dian Road
Pudong New Area, Shanghai 201204
P.R. China
+86 21 8017 1200

Mark A. Leahy

Co-Chair, Startup & Venture Capital

Partner, Corporate  

Mountain View 650.335.7682


Mark Leahy, a seasoned advisor to technology companies on a broad range of corporate transactional matters, focuses on providing legal solutions that advance his clients’ business objectives. With a deep understanding of each client’s business and competitive landscape, Mark provides practical guidance through the complex legal and business hurdles of company growth. He enjoys learning about each of his clients, understanding their needs, and playing a central role in their business transactions.

Mark’s practice focuses on venture capital financings, corporate governance, mergers and acquisitions, and public offerings. His expertise spans a wide range of technologies, including software, semiconductor, internet/e-commerce, and data management and storage.

His client roster is comprised of companies at all stages of development – from entrepreneurs seeking company formation advice, to startups seeking additional funding, to public company acquirers in search of targets in the technology space.

Representative Transactions

  • Represented ParAccel, a company in the big data analytics space, in its last set of financing rounds and its acquisition by database vendor Actian
  • Represented Pulse news reader maker Alphonso Labs in all of its financing rounds and its acquisition by LinkedIn
  • Represented approximately 50 startup companies over the last three years in their various types of financing transactions

Professional Achievements

  • Mark was recognized as a “Leading Lawyer” in the 2013 The Legal 500 in the areas of Venture Capital and Emerging Companies.
  • Mark served for eleven years as a board member of the Churchill Club, a Silicon Valley business and technology forum, and is a Board Emeritus member.

What Can You Expect When You Work with Mark?

Working with Mark means having a strategic partner who knows your business, maintains strong relationships with your executive team and board members, and is dedicated to superior client service. No matter how your company changes or grows, Mark will be a readily accessible resource for sound legal solutions and business advice.

More About Mark

Prior to law school, Mark had a career as an engineer at an aerospace company.

He enjoys returning every year to his law school alma mater, the University of Chicago, where he is actively involved in recruiting new students into the legal profession.

In his free time, Mark loves to hang out with his children and take part in their hobbies – including running and skateboarding.