The following is an excerpt from Practice Perspectives: Vault's Guide to Legal Practice Areas.
Heather Nyong’o is Co-leader of Cleary Gottlieb’s U.S. antitrust group. Her practice focuses on antitrust enforcement, including governmental and criminal investigations, international cartel disputes, merger clearance, and complex civil and criminal litigation.
With over two decades of white collar and antitrust experience, Heather is a seasoned litigator and skilled first-chair trial lawyer. She regularly represents major multinational corporations and executives in complex investigations and litigation in the United States and abroad. Heather fully serves her clients across every phase of investigations and litigation, including through trial. She has led multiple notable cases for individuals and corporations in nonpublic grand jury investigations.
After spending nearly a decade working in the Antitrust Division of the DOJ, Heather brings a wealth of experience in government investigations, particularly those that result in criminal or civil litigation. She won the Attorney General’s Award, the DOJ’s second-highest honor, and handled some of the agency’s most significant investigations and criminal prosecutions in recent years. After her time at the DOJ, Heather developed and led a successful antitrust, complex civil and criminal litigation, and enforcement investigations practice at another prominent firm in California, where she served as the partner-in-charge of that firm’s San Francisco office.
Describe your practice area and what it entails.
Cleary has a preeminent antitrust practice that is widely recognized as the best in the world. With a strong presence on both sides of the Atlantic, we are unmatched in our ability to advise efficiently on the full range of cross-border matters and serve as a destination practice for any company facing complex antitrust issues. Our team is renowned for its strength across all areas of antitrust law, from sophisticated merger clearance to multi-jurisdictional criminal and civil investigations and complex litigation.
My practice focuses on antitrust enforcement and litigation, including civil litigation, grand jury investigations, and merger challenges. Before joining Cleary, I spent a decade as a DOJ prosecutor, which gives me unique insight into how government enforcers approach cases. At any given time, I’m defending merger transactions, navigating cartel investigations, and representing clients in antitrust litigation.
What types of clients do you represent?
I represent a broad range of clients—from global companies in technology, consumer products, health care, and sports to founders and individuals. I also work with private equity portfolio companies and startups navigating competition issues as they scale. One of the things I enjoy most about my practice is the diversity of industries; each client brings a new set of business challenges and competitive dynamics to understand.
What types of cases/deals do you work on?
My practice spans antitrust investigations and litigation, including grand jury work, civil and criminal matters, and merger challenges brought by the government. In the past year, I represented GTCR and Tempur Sealy (now Somni-group International) in merger litigation and clients such as Humana, Pratt & Whtiney, GMO-Z.com Trust Company, and the International Tennis Federation in civil litigation.
At the DOJ , I led and tried complex antitrust cases. Today, I regularly defend companies in cartel investigations, represent clients in high-stakes merger litigation, and counsel on conduct matters such as pricing, distribution, and competitor collaborations. I work on a mix of matters helping clients navigate DOJ or FTC investigations, defending merger transactions under government scrutiny, and advising on day-to-day antitrust compliance issues.
How did you choose this practice area?
After college, I worked as a paralegal in Washington, DC, and was assigned to the U.S. government’s landmark case against Microsoft. Being on the trial team preparing witnesses, man-aging evidence, and seeing strategy come together in real time hooked me on antitrust. I went to law school with this focus, practiced at a firm after graduation, and then seized an opportunity to join the DOJ in California, where I deepened my trial and investigative experience. It was the perfect combination of law, economics, and high-stakes problem-solving. I love the intellectual challenge and the fact that antitrust sits at the intersection of business strategy and legal analysis.
What is a “typical” day like and/or what are some common tasks you perform?
There’s no typical day, which is one of the things I love most about this practice. Some days, I’m preparing a client for a government interview or mapping out a merger defense strategy; other days, I’m getting ready for trial. As a Co-leader of the U.S. antitrust group, I also spend time on team building and strategy thinking about how to grow our practice, develop talent, and deliver client value. I interact regularly with clients, government enforcers, co-counsel, and economic experts. I travel often, so my schedule shifts between client meetings, hearings, and internal mentoring. The variety keeps the work fresh and intellectually engaging.
What training, classes, experience, or skills development would you recommend to someone who wishes to enter your practice area?
If you can take an Antitrust class, you should. An economics background helps, but it’s not required; many of our associates come to the firm with only limited economics training and thrive with a commitment to learning. Courses in evidence, administrative law, and M&A are also useful. More broadly, build strong writing and analytical skills, get comfortable with data and expert reports, and seek experiences that develop judgment: clinics, moot court, trial advocacy, or internships with enforcement agencies like the FTC or DOJ. I also recommend joining the ABA Antitrust Section once you’re in practice to continue learning and building a network. If you have the opportunity to work for the government at some point in your career, I highly recommend it; the experience is invaluable.
What do you like best about your practice area?
Antitrust lets you learn new industries and new legal questions every day. The matters are often high-stakes—some-times truly bet-the-company—and they sit at the intersection of law, business strategy, and economics. I enjoy helping clients make critical decisions, and I appreciate that the field evolves constantly through cases, policy, and market changes so you’re always learning and contributing to how the law develops. The intellectual challenge is real, and the work has immediate, tangible impacts on clients’ businesses.
What misconceptions exist about your practice area?
A common misconception is that you need to be an economist to practice antitrust. Economics matters, but the core of the practice is clear thinking, strong writing, and practical judgment. We work with expert economists; your job is to frame the issues, test the evidence, and tell a compelling story. Another misconception is that antitrust is a niche or support practice. There’s a very large antitrust bar, and the work includes agency merger reviews, civil litigation, and criminal cartel investigations. At Cleary, antitrust is a destination practice that is strategically critical to the firm.
What is unique about your practice area at your firm?
Many firms separate antitrust into narrow silos: litigation, mergers, or white collar. At Cleary, we encourage breadth. Our lawyers work across merger review and litigation, criminal cartel investigations, civil conduct cases, and counseling. This range makes you a more complete antitrust lawyer and lets you build judgment that translates across matters. Antitrust is a flagship practice here, not a support function; it’s strategically critical to the firm. We’re also unique in having a top-tier practice in both the United States and Europe, so we handle truly global matters with seamless coordination across offices.
What kinds of experiences can summer associates gain in this practice area at your firm?
Summer associates get hands-on experience. Recent projects include helping prepare witnesses, assisting with grand jury matters, and drafting research that feeds into deposition prep and court arguments. You’ll see how clients decide whether and how to self-report and cooperate with the government. You may also join strategy sessions and pitch preparation, which opens a window to see the business of a practice. Summer associates learn about the client’s business and the competition it faces, and they’re involved in factual and legal research, risk assessment advice, and advocacy with respect to antitrust agencies. The exposure to multiple industries over a short period gives you invaluable insights into the global business world.