Who's Who Legal Switzerland

“a star advocate”

Who's Who Legal

“probably the best arbitration counsel of the young generation”

Legal 500

“never misses a single detail”

Who's Who Legal

“his care of the client is impressive”

40 under 40

“amongst the most promising rising stars in international arbitration”

Who's Who Legal Switzerland

“praised for his multifold expertise in investment arbitration”

Who's Who Legal

“tremendously talented”

Who's Who Legal

“a brilliant mind”

Who's Who Legal

“great advocacy skills”

Who's Who Legal

“a top person to contact in Europe for complex arbitration matters”

Sebastiano Nessi

Sebastiano Nessi is a Counsel specializing in international arbitration. He represents clients in international commercial, investment and sports arbitration matters as well as in enforcement and setting-aside proceedings before the Swiss Supreme Court. He has also advised states on the negotiation and drafting of investment treaties, and investors on the (re)structuring of their investments. A Swiss national, Sebastiano sits frequently as an arbitrator (president of the tribunal, sole arbitrator and co-arbitrator).

Sebastiano is ranked as one of the 10 Most Highly Regarded lawyers (Future Leaders) in Europe Middle East, Africa (EMEA) by Who’s Who Legal Arbitration. He is also recognized as a National Leader and comes highly recommended by Who's Who Legal Switzerland and Legal500. According to clients and peers, Sebastiano is "tremendously talented", "brilliant", "very sharp and efficient", and he is lauded for his "great advocacy skills" and his "impressive client management skills" (Who’s Who Legal). Other sources praise him for being "a star advocate" (Who's Who legal Switzerland) and a "strong academic" with "multifold expertise in investment arbitration", "who never misses a single detail" and "is always the first to propose an excellent legal solution" (Legal500), and report that he is "probably the best arbitration counsel of the young generation" (Who’s Who Legal Switzerland). Impressed clients remark that "his deep understanding of issues of damages stand out, which contributes a lot to each and every case" (Legal500). He is also recognised as "a top person to contact in Europe for complex arbitration matters" (Who’s Who Legal), and one of the "most promising rising stars in international arbitration" (40 under 40 / LMG Expert Guide). Sebastiano is a Fellow of the Chartered Institute of Arbitrators in London.


  •  Has acted as counsel for Swiss and international clients (including states and state-owned entities) in a range of complex (commercial and investment) arbitrations, both ad hoc and under each of the major institutional rules, with seats in Geneva, London, New York, Paris, Singapore, Stockholm and Vienna
  • Has  represented clients on a range of court applications before Swiss courts including the Swiss Supreme Court
  • Has advised clients on the structuring of their investment and states on the negotiation and drafting of trade and investment treaties
  • Has a broad range of expertise with a particular focus on energy, oil & gas, commodities, pharmaceuticals, sales and distribution, banking, aerospace, construction and sports disputes
  • Sits himself as an arbitrator 


Professional Experience
Counsel at Schellenberg Wittmer
Senior Associate at Schellenberg Wittmer
Senior Associate at Allen & Overy LLP, Paris
Associate in a major Swiss law firm in Geneva
Education and Admission
Fellow Chartered Institute of Arbitrators (FCIArb)
Certificate of Advanced Studies in Arbitration, University of Lucerne and University of Neuchâtel
Arbitration Practitioner (ArbP) Diploma, Swiss Arbitration Academy
LL.M., Columbia Law School, New York
Bar Admission in Switzerland
Master of Law, University of Geneva
Additional Professional Activities
  • Vice-chair of the Chartered Institute of Arbitrators' Young Members Group (CIArb YMG)
  • Member of the Chartered Institute of Arbitrators' (CIArb) Professional Development Advisory Group
  • Lecturer on commercial and investment arbitration at the University of Paris I, Panthéon-Sorbonne, Sciences Po Law School, the Swiss Arbitration Academy, and the Ukrainian Arbitration Association's Arbitration School
  • International Chamber of Commerce (ICC YAF) Representative for Europe and Russia (2019-2021)

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