William Ong

William Ong is a Partner and Co-Head of the Litigation & Dispute Resolution Department at Allen & Gledhill, specialising in dispute resolution, international arbitration, banking litigation, and corporate insolvency and restructuring. He represents clients in corporate disputes, including shareholder and directors' disputes, joint venture disputes, minority oppression claims, breach of directors' duties, misappropriation of company property, and disputes arising from M&A transactions. He has a special interest in the assessment of damages and valuation methodology, which is valued by clients for its technical and legal depth.

William has acted for an insurer in a US$200 million dispute between an insurer and a bank spanning arbitration in Taiwan and court proceedings in Singapore, involving fraud, trust and investment structures across multiple jurisdictions, and the validity of security. He also acted in a dispute between Malaysian and Chinese parties over the due diligence process in an aborted acquisition deal, and for the liquidator in seeking to recover S$60 million or more from a director and controlling shareholder of the Park Hotel Group arising from claims at an undervalue, declared dividends, and transfer of receivables.

William holds an LL.B. (Hons) from the National University of Singapore and was called to the Singapore Bar in 2000. He joined the firm in 2000 and has been a Partner since 2006.

He is recognised as being able to "clearly identify a litigation strategy and prepare the case accordingly" and has "the ability to break complex matters into manageable steps" (The Legal 500 Asia Pacific 2024). He was also listed in the Top 30 Litigators 2025 by Asian Legal Business. He serves as Deputy Chairman of the Singapore Chinese Orchestra.