Helgi Walker is a partner in Gibson Dunn’s Washington, D.C. office. She is co-chair of the firm’s global Litigation Practice Group and recently served as a member of the firm’s Executive Committee. She is also co-chair of the Administrative Law and Regulatory Practice Group and a member of the Appellate and Constitutional Law Group. Chambers USA describes her as “dynamite in the courtroom and a forceful oral advocate,” “a brilliant legal mind,” and counsel with “excellent judgment” and “a reputation for excellence.”
Helgi’s work focuses on appellate, regulatory and complex litigation matters. She has extensive experience in appellate challenges to agency rulemakings and in other high-stakes commercial litigation.
Helgi was elected as a Fellow of the American Academy of Appellate Lawyers, limited to 500 lawyers nationwide. She also is a member of the U.S. Chamber of Commerce’s Administrative Law & Government Litigation Advisory Committee. By appointment of the U.S. Court of Appeals for the D.C. Circuit, Helgi served as the Chair of the Court’s Advisory Committee on Procedures from 2017-2024. From 2010 to 2015, she was a Public Member of the Council of the Administrative Conference of the United States, composed of leading authorities on administrative law.
Helgi worked in the White House Counsel’s Office as Associate Counsel to President George W. Bush from 2001 to 2003.
Helgi clerked for U.S. Supreme Court Justice Clarence Thomas from 1995 to 1996 and Judge J. Harvie Wilkinson III of the U.S. Court of Appeals for the Fourth Circuit from 1994 to 1995.
Helgi is listed as a leading lawyer in Appellate Law Telecom, Broadcast & Satellite and Commercial Litigation by Chambers USA. In its 2020 competition, The American Lawyer named Gibson Dunn the Litigation Department of the Year and a finalist in the White Collar/Regulatory category that includes her practice areas. In 2011, The American Lawyer selected her as one of the “45 Under 45,” “best of the best among young women lawyers” in the United States. The National Law Journal named her one of “Washington’s Most Influential Women Lawyers” in 2011. Washingtonian magazine has repeatedly recognized her as one of D.C.’s “Top Lawyers” in its biennial rankings, including in the Supreme Court (2022) and Communications (2024) categories, and among “The Power 100” of “influential players running Washington and the world” (2014-2015).
In addition, she was :
- Named The American Lawyer’s “Litigator of the Week” for securing a ruling blocking the FTC’s “Click to Cancel” rule (2025).
- Named The American Lawyer’s “Litigator of the Week” runner-up for securing a writ of mandamus from the Fifth Circuit ordering the FTC to comply with the federal lottery statute (2024).
- Named The American Lawyer’s “Litigator of the Week” runner-up for successful challenge to the SEC’s dealer rule (2024).
- Named by Benchmark Litigation as a “Litigation Star” (2026).
- Named by Benchmark Litigation as a “National Practice Area Star” in Appellate (2026).
- Named one of Benchmark Litigation’s “Top 250 Women in Litigation” in the country (2021-2025).
- Named by Lawdragon as one of the “500 Leading Litigators in America” (2024-2026).
- Named by Lawdragon as a “Lawdragon Legend” (2021), one of only 32 lawyers nationwide recognized as “the biggest stars” who have demonstrated “sustained excellence and endurance.”
- Named by Client Choice Awards as the winner of the District of Columbia Litigation category (2018).
- Named by Law360 as a Telecommunications MVP (2016), observing that her work “has spanned the industry” including a “big win” for broadcasters in “a major ownership case.”
- Named by Law360 as an Appellate MVP (2015), describing her as a “go-to counsel for high-stakes appellate challenges of federal agency actions” and “leading cutting-edge litigation for a range of industries.”
- Named The American Lawyer’s “Litigator of the Week” for her win on behalf of Ford Motor Company before the en banc Sixth Circuit in a case involving telecommuting under the Americans with Disabilities Act (2015).
- Named The American Lawyer’s “Litigator of the Week” for her win on behalf of Verizon in the “major appeals court ruling” overturning the FCC’s “net neutrality” regulation of Internet service providers (2014).
- Named The American Lawyer’s “Litigator of the Week” for obtaining a “blockbuster appellate decision” for Comcast in a challenge to the FCC’s first “net neutrality” decision (2010).
Representative Matters:
- Represented the Dewberry Group in U.S. Supreme Court in 9-0 victory in appeal regarding trademark remedies.
- Represented the National Association of Broadcasters and other media and newspaper industry parties as lead counsel in the U.S. Supreme Court in defense of the FCC’s repeal or modification of restrictive and outdated local media ownership rules, arguing the case and winning 9-0.
- Represented the Interactive Advertising Bureau, NCTA, the U.S. Chamber of Commerce, NFIB, and others comprising a broad coalition of trade associations and businesses challenging the FTC’s “click to cancel” rule, obtaining vacatur of the entire rule in the Eighth Circuit just days before it was set to take effect, as well a prior mandamus order from the Fifth Circuit directing the agency to comply with the federal lottery statute governing multi-circuit petitions for review.
- Represented the National Association of Broadcasters in latest challenge to FCC media ownership rules in the Eighth Circuit, securing vacatur of rule prohibiting broadcasters from owning more than one top-four-rated television station and establishing precedent that the Telecommunications Act of 1996 does not allow tightening of the rules only deregulation.
- Represented the National Association of Private Fund Managers, and other private funds trade associations, in winning Fifth Circuit challenge to SEC rule asserting proscriptive authority over private funds, securing vacatur of the entire rule.
- Represented the National Association of Private Fund Managers, and other private funds trade associations, in successful N.D. Texas challenge to SEC’s “dealer” rule, resulting in vacatur of entire rule.
- Representing T-Mobile in D.C. Circuit appeal of FCC enforcement action imposing $80 million penalty regarding location data.
- Represented CTIA-The Wireless Association in the D.C. Circuit in successfully upholding the FCC’s “Restoring Internet Freedom Order” repealing the “net neutrality” regime and most recently in overturning the subsequent reinstatement of those rules in the Sixth Circuit.
- Represented Verizon in successful D.C. Circuit appeal of the FCC’s order formally adopting “net neutrality” rules, obtaining vacatur of the rules.
- Represented Comcast in successful D.C. Circuit appeal of the FCC’s first “net neutrality” decision, securing vacatur of that decision.*
- Represented PHH Corporation in D.C. Circuit appeal of CFPB action under the Real Estate Settlement Procedures Act of 1974—the first appellate challenge to a CFPB enforcement proceeding—and successfully procured a stay of the agency order pending appeal and victory on the merits in a historic separation of powers ruling at the panel level, ultimately prevailing before the en banc court on administrative law grounds and securing vacatur of $109 million penalty.
- Appointed by the U.S. Supreme Court to brief and argue the case in defense of the judgment below in Welch v. United States, involving the retroactivity of new rules on habeas review.
* Matter handled prior to joining Gibson, Dunn & Crutcher LLP.
Helgi graduated in 1994 from the University of Virginia School of Law, where she was a member of the Order of the Coif and Raven Society and served as Executive Editor of the Virginia Law Review. She also received the Robert E. Goldsten Award and John M. Olin Prize in Law and Economics.
Helgi is admitted to practice in the District of Columbia.
Capabilities
- Appellate and Constitutional Law
- Administrative Law and Regulatory Practice
- Consumer Protection
- Litigation
- Trials
Credentials
Education:
- University of Virginia - 1994 Juris Doctor
- University of Virginia - 1988 Bachelor of Arts
Admissions:
- District of Columbia Bar
Clerkships:
- US Supreme Court, Hon. Clarence Thomas, 1995 - 1996
- US Court of Appeals, 4th Circuit, Hon. J. Harvie Wilkinson III, 1994 - 1995