[5] On 20 November 2012, Commonwealth Attorney-General Nicola Roxon announced Allsop would be appointed Chief Justice of the Federal Court of Australia.

In January 2022, he presided over the application for judicial review regarding the visa status of Novak Djokovic on the Full Bench of the Federal Court of Australia.

In March 2022 he presided over the Court's ruling that the Commonwealth Minister for the Environment has no duty of care to protect children from the impacts of climate change when considering fossil fuel projects, a ruling that was characterised as undoing "20 years of climate litigation progress in Australia"[6] and demonstrating the "yawning crevasse between the facts in the real world and Australian "environmental" law".

also an adjunct professor at the University of Sydney, where he specialises in international admiralty and maritime law.

[citation needed] In April 2024, Justice Allsop gave the keynote speech at the Fifth Full Meeting of the Standing International Forum of Commercial Courts.