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Dyana Mardon

Dyana Mardon

Associate, San Antonio
210.978.7740
dmardon@jw.com
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Biography Recognition & Accolades Publications & Speeches News & Insights
Dyana Mardon

Dyana K. Mardon

Associate, San Antonio
210.978.7740
dmardon@jw.com
Email LinkedIn vCard Print
Recognition & Accolades Publications & Speeches Attorney News

Practice Areas

  • Trial & Appellate Litigation

Experience

  • Investigations & White Collar Defense
  • National Security and International Trade
  • South Korea

Biography

Dyana Mardon helps clients navigate high-stakes disputes and investigations, bringing clarity and decisive advocacy to complex legal problems. She represents clients in commercial litigation, employment disputes, trust and estate litigation, and government investigations and enforcement actions, helping them protect their interests and pursue a clear path toward resolution.

Dyana counsels clients on U.S. export controls, import regulations, trade sanctions, and trade compliance programs, internal procedures, and regulatory policies. She also advises clients on compliance with CFIUS regulations and AFIDA at the national level, and SB 17 and the Lone Star Infrastructure Protection Act in Texas.

Dyana brings local and international policy experience through her prior work with the City of Oakland Public Ethics Commission, the United Nations Economic and Social Commission for Asia and the Pacific (UNESCAP) in Bangkok, Thailand, and the Global Green Growth Institute in Seoul, South Korea.

Education

B.A., University of California Berkeley

M.P.P., University of California Berkeley, Goldman School of Public Policy

J.D., University of California Berkeley School of Law

Bar Admissions

California
Texas

Court Admissions

U.S. District Court for the Northern, Eastern, Western, and Southern Districts of Texas

U.S. District Court for the Northern, Central, Eastern, and Southern Districts of California

U.S. Court of Appeals for the Ninth Circuit

U.S. Court of International Trade

  • “Best S.A. Lawyers,” San Antonio Scene, 2023-2024, 2026
    • Business Litigation
    • Business & Contracts
    • General Litigation
  • “Outstanding Women in Law,” San Antonio Scene, 2026
  • Best Lawyers: Ones to Watch (Woodward/White Inc.)
    • Commercial Litigation, 2025-2026

  • Co-author, “How Companies can Protect their Rights to IEEPA-based Tariff Refunds,” Jackson Walker Insights (March 2026)
  • Co-author, “Supreme Court Rules IEEPA Does Not Authorize Tariffs,” Jackson Walker Insights (February 2026)

Congratulations to Jackson Walker’s Best Lawyers and Ones to Watch - 360 attorneys recognized, 12 Lawyers of the Year, 238 Best Lawyers honorees, and 122 Ones to Watch honorees
‘The Best Lawyers in America’ Features 360 Jackson Walker Attorneys in 2027 Edition, Including 12 “Lawyers of the Year” and 122 “Ones to Watch”

The Best Lawyers in America has recognized 360 Jackson Walker attorneys across 82 specialty practice areas in its 2027 edition, including 12 Lawyers of the Year and 122 Ones to Watch. Best Lawyers listings are based on an exhaustive peer review survey of thousands of attorneys who vote on the legal abilities of others in their practice areas. For over three decades, recognition in Best Lawyers has been regarded by both clients and legal professionals as a significant honor, since an attorney cannot pay to be listed.

Attorney News • August 20, 2026

The U.S. Government Appeals IEEPA Tariff Refund Order — What Importers Need to Know Now

By Dyana Mardon, Cameron A. Secord, and Robert L. Soza

As we discussed in our prior publications (Supreme Court Rules IEEPA Does Not Authorize Tariffs and How Companies Can Protect Their Rights to IEEPA-based Tariff Refunds), the Supreme Court’s February 20, 2026 decision in Learning Resources, Inc. v. Trump held that IEEPA does not authorize the President to impose tariffs, and importers have since pursued various paths to recover the unlawfully collected duties.

Insights • June 17, 2026

‘Scene in SA’ Recognizes Jackson Walker Attorneys in 2026 “Best SA Lawyers” List

Jackson Walker proudly congratulates the 49 attorneys in the San Antonio office who were included in Scene in S.A.’s 2026 “Best SA Lawyers” list.

Attorney News • May 18, 2026

How Companies can Protect their Rights to IEEPA-based Tariff Refunds

By Dyana Mardon, Cameron A. Secord, and Robert L. Soza

On February 20, 2026, the Supreme Court ruled (6-3) that IEEPA does not allow the President to impose tariffs. See our prior publication on this decision here: Supreme Court Rules IEEPA Does Not Authorize Tariffs. The majority explained that imposing tariffs is a core power reserved for Congress, and while IEEPA allows the President to “regulate…importation,” it does not include the power to tax or impose tariffs.

Insights • March 12, 2026

Supreme Court Rules IEEPA Does Not Authorize Tariffs

By Dyana Mardon, Cameron A. Secord, and Robert L. Soza

On Friday, February 20, the Supreme Court in Learning Resources, Inc. v. Trump held that the International Emergency Economic Powers Act (IEEPA) does not authorize the President to impose tariffs. The decision resolves consolidated challenges to certain IEEPA based tariffs—including a 25% duty on most Canadian and Mexican imports, 10–20% on Chinese imports, and a baseline 10% “reciprocal” tariff on all trading partners.

Insights • February 21, 2026

USA flags
‘The Best Lawyers in America’ Features 350 Jackson Walker Attorneys in 2026 Edition, Including 10 “Lawyers of the Year” and 106 “Ones to Watch”

The Best Lawyers in America, a widely regarded guide to legal excellence, has recognized 350 Jackson Walker attorneys across 87 specialty practice areas in its 2026 edition, including 10 Lawyers of the Year and 106 Ones to Watch.

Attorney News • August 21, 2025

JW Belonging & Inclusion Newsletter – May 2025

View Jackson Walker’s May 2025 Belonging & Inclusion Newsletter, Perspectives.

Newsletters • May 30, 2025

Best Lawyers 2025 edition graphic - 306 attorneys recognized, 81 specialty areas, 75 Ones to Watch, and 9 Lawyers of the Year
‘The Best Lawyers in America’ Features 306 Jackson Walker Attorneys in 2025 Edition, Including 9 “Lawyers of the Year” and 75 “Ones to Watch”

The Best Lawyers in America has recognized 306 Jackson Walker attorneys across 81 specialty practice areas in its 2025 edition, including 9 Lawyers of the Year and 75 Ones to Watch. In this year’s guide, Jackson Walker saw the largest number of attorneys in the areas of Commercial Litigation (75 attorneys) and Real Estate Law (55 attorneys) and the addition of 27 attorneys as Best Lawyers.

Attorney News • August 15, 2024

JW Diversity & Inclusion 2022 Report theme
JW Diversity & Inclusion Newsletter – December 2023

View Jackson Walker’s December 2023 Diversity & Inclusion Newsletter, Perspectives.

Newsletters • December 4, 2023

Jackson Walker San Antonio
‘Scene in S.A.’ Recognizes Jackson Walker Attorneys in 2023 “Best S.A. Lawyers” List

Jackson Walker congratulates the 44 practicing attorneys in the San Antonio office who were included in Scene in S.A.’s 2023 “Best S.A. Lawyers” list. In its 19th year, the “Best S.A. Lawyers” list presents attorneys across 80 distinct practice areas who were nominated by fellow licensed, practicing attorneys of Bexar County.

Attorney News • September 18, 2023

JW Diversity & Inclusion 2022 Report theme
JW Diversity & Inclusion Newsletter – April 2023

View Jackson Walker’s April 2023 Diversity & Inclusion Newsletter, Perspectives.

Newsletters • April 24, 2023

More Attorney News

Recognition & Accolades

  • “Best S.A. Lawyers,” San Antonio Scene, 2023-2024, 2026
    • Business Litigation
    • Business & Contracts
    • General Litigation
  • “Outstanding Women in Law,” San Antonio Scene, 2026
  • Best Lawyers: Ones to Watch (Woodward/White Inc.)
    • Commercial Litigation, 2025-2026

Publications & Speeches

  • Co-author, “How Companies can Protect their Rights to IEEPA-based Tariff Refunds,” Jackson Walker Insights (March 2026)
  • Co-author, “Supreme Court Rules IEEPA Does Not Authorize Tariffs,” Jackson Walker Insights (February 2026)

Practice Areas

  • Trial & Appellate Litigation

Experience

  • Investigations & White Collar Defense
  • National Security and International Trade
  • South Korea

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