Derek On

Derek On

Partner, Rajah & Tann Singapore LLP

Practice Area:

Commercial Litigation

LLB (Hons), National University of Singapore
Advocate & Solicitor, Singapore

T +65 6232 0785

Derek is a Partner with the firm’s Commercial Litigation practice. 

He regularly advises and acts for institutions and individuals in commercial disputes.

Derek has a wide range of experience in banking and securities litigation, shareholders’ disputes, arbitration-related litigation, and employment-related disputes.

His experience includes a placement with Fountain Court Chambers in London (as a recipient of the SAL Overseas Attachment Award) where he assisted silks in complex commercial matters before English courts and international tribunals. Derek was also seconded to the APAC litigation and investigations group of an international bank.

Prior to joining the firm, Derek graduated on the overall Dean’s List from the National University of Singapore in 2011. He is currently an advocacy trainer for Part B students at the Singapore Institute of Legal Education.


Notable cases and transactions include:

  • Successfully defended a global bank against claims exceeding US$10 million brought by private banking clients over losses suffered due to the Madoff Ponzi scheme
  • Acted for a global bank in successfully resisting a complaint for breach of banking secrecy laws
  • Acted for a bank in successfully recovering a multi-million dollar claim against a businessman
  • Acting for a global resources company in defending allegations of market manipulation
  • Defending a claim in the SICC involving alleged wrongful payments of over US$23 million paid out by offshore companies
  • Acted for an international coal company in a claim against a former director and his affiliates for breach of fiduciary duties and successfully obtaining a Mareva injunction against them
  • Acting for an overseas conglomerate to resist the enforcement of a US$200 million SIAC award in Singapore
  • Acted for an investment and financial consultant in defending claims of mis-selling
  • Acted for and advised a leading markets operator and an international financial software company on employment-related issues
  • Acted for and advised the chairman of a publicly-listed company in a special audit on past transactions

Notable judgments include:

  • TMT Asia Ltd v BHP Billiton Marketing AG (Singapore Branch) and another [2018] SGHC 228
  • Tradewaves Ltd and others v Standard Chartered Bank and another suit [2017] SGHC 93
  • TMT Asia Ltd v BHP Billiton Marketing AG (Singapore Branch) and another [2015] 2 SLR 540
  • AYH v AYI and another [2015] SGHC 300
  • AYK and another v AYM [2015] SGHC 329
  • Member, Singapore Academy of Law
  • Member, Law Society of Singapore