Steven Tonsfeldt is a partner in O’Melveny’s Silicon Valley office and Chair of the Mergers & Acquisitions Practice.

Steven’s practice focuses primarily on the representation of publicly traded and privately held companies in both domestic and cross-border merger and acquisition transactions, leveraged buyout transactions, significant recapitalizations, corporate partnering arrangements, the formation of joint ventures and other strategic alliances, minority equity investments, and other similar transactions. He has also represented financial sponsors in various forms of leveraged acquisitions as well as financial advisors who are advising companies engaged in acquisition transactions.

Over the past several years, Steven has led lawyer teams in acquisition transactions having an aggregate value of well over US$100 billion. During the course of this work, he has represented a number of corporate clients in acquisition transactions involving some of the world's most active participants, including transactions with companies like Yahoo!, Google, Cisco Systems, Microsoft, Dell, Samsung, Intel, Qualcomm, Nokia, Merck and Time Warner.

Prior to law school, Steven worked as a certified public accountant with Deloitte & Touche. He also taught accounting at UC Berkeley’s Haas School of Business as a graduate student instructor.

Steven has been selected for inclusion in Chambers USA: America’s Leading Lawyers for Business for more than a decade and has been named the Dealmaker of the Week by the American Lawyer. He has also been recognized as a leading corporate lawyer in The Best Lawyers in America, PLC Which Lawyer? and The Legal 500.