​Penny Madden is an English qualified Queen’s Counsel and partner in the London office of Gibson, Dunn & Crutcher. She is Co-Chair of the International Arbitration Practice Group and a member of the firm’s transnational Dispute Resolution Practice Group.

She has a wide range of experience in all key aspects of international arbitration with particular expertise in shareholder, telecommunications, SPA, energy, international trade and insurance disputes. She represents clients across the globe in a wide variety of arbitration proceedings, including those before the London Court of International Arbitration (LCIA), International Chamber of Commerce (ICC), United Nations Commission on International Trade Law (UNCITRAL), International Centre for Settlement of Investment Disputes (ICSID), Permanent Court of Arbitration in The Hague (PCA) Singapore International Arbitration Centre (SIAC), Hong Kong International Arbitration Centre (HKIAC) and London Maritime Arbitrators Association (LMAA), as well as in ad hoc proceedings. In addition to representing clients as counsel and advocate, Ms. Madden regularly sits as an arbitrator.

Her recent cases include representing a telecommunications corporate in its US$17 billion dollar UNCITRAL investment treaty arbitration against a North African state for creeping expropriation and breach of the fair and equitable treatment standard; representing a major mining corporate in a US $1.4 billion LCIA arbitration dispute arising out of mining investments in Brazil; representing a Middle East oil and gas company in a multi-billion LCIA arbitration arising out of an oil and gas project in Kurdistan; representing a syndicate of insurers in a multi-million dollar ICC arbitration for coverage of a pan-African joint venture; representing a global corporate in its US$1.6 billion dollar ICSID investment treaty arbitration against a sovereign state arising out of expropriation of extensive mining investments; and representing shareholders in a major oil company with respect to multibillion dollar claims for expropriation under the Energy Charter Treaty against the Russian Federation.

She is a member of the LCIA, CIArb, the Financial Sector Arbitration Group and the editorial board of Commercial Dispute Resolution. She writes and lectures on a wide variety of arbitration issues and is the international arbitration specialist for the Diplomatic Book and Website for foreign Embassies and High Commissions. Ms. Madden is recommended for International Arbitration and Public International Law in Legal 500 UK 2021.  Chambers UK 2021 and Chambers Global 2020 recommends Ms. Madden as a leading lawyer for International Arbitration and describes her as “absolutely superb. She is no-nonsense, super smart and has excellent written advocacy skills.” She is also noted as a “strong advocate” who clients consider to be “extremely hard-working”. She has also been described as “very business-oriented” with “great analytical skills” and “always available for her clients.” Best Lawyers UK recommends Ms. Madden in the field of International Arbitration (2019-2021), she is listed as an expert in Arbitration in Who’s Who Legal 2020, and is also ranked as a ‘Litigation Star’ for International Arbitration by Benchmark Litigation Europe 2020.  Ms Madden’s team won Arbitration Team of the Year 2020 in the British Lawyer Awards for its representation of a mining investor in relation to an ICSID investment treaty arbitration against a sovereign state.

Ms. Madden received her Bachelor of Arts in 1990 from University of Oxford, St. Hugh’s College, and her Law Society Finals in 1992 from University of Law, Guildford.  She took silk in 2016.