He was appointed to the Court of Final Appeal of Hong Kong on 8 April 2013 as a non-permanent judge from other common law jurisdictions.

It also included large constitutional issues and in several cases he appeared as a junior to then Commonwealth Solicitor-General, Maurice Byers.

[3] On 8 April 2013, he was appointed to the Court of Final Appeal of Hong Kong as a non-permanent judge from other common law jurisdictions.

Gummow's judgments are notable for their careful attention to statutory language and context, and are marked by a thorough and scholarly examination of doctrinal history.

However, some of his more notable individual opinions include: Breen v Williams, Kable v Director of Public Prosecutions for New South Wales, The Wik Peoples v The State of Queensland, Hill trading as R F Hill & Associates v Van Erp, Pyrenees Shire Council v Day, Scott v Davis, Roxborough v Rothmans of Pall Mall, and Al-Kateb v Godwin.

See, for example: Werner & Co v Bailey Aluminium Products (1989), Advanced Building Systems v Ramset Fasteners (1998), Prestige Group v Dart Industries (1990), ConAgra v McCain Foods (1992).

Statistics in recent years have consistently shown Justice Gummow to be most likely to participate or be joined in a majority opinion.

Gummow also wrote, with Dyson Heydon and Robert Austin, several editions of Cases and Materials on Equity and Trusts (4th ed, 1993).