Mortimer did her articles at Goldberg and Window Solicitors before becoming an associate to
Sir Gerard Brennan, then a justice of the
High Court of Australia in 1988 and 1989. Mortimer became a
barrister in 1989 and was appointed as a Senior Counsel in 2003. however, Mortimer was an exception, until her elevation as a judge. Her appearances included for the successful applicants in
Plaintiff M61/2010E v Commonwealth, and
Plaintiff M70/2011 v Minister for Immigration and Citizenship. Mortimer also appeared in environmental cases, including representing
Bob Brown, an
Australian Greens Senator, in a case against
Forestry Tasmania, concerning the
Wielangta forest. As well as an active practice as a barrister, Mortimer was a lecturer in the
Monash University Faculty of Law from 1991 to 1994 and at the
University of Melbourne Law School from 2011. including the way they had investigated the death in custody, that an emergency declaration and the deployment of the
Special Emergency Response Team was part of an excessive and disproportionate policing response. Mortimer was the trial judge in a case brought by
Consumer Affairs Victoria against wellness blogger
Belle Gibson and her companies for misleading or deceptive conduct and unconscionable conduct contrary to the
Australian Consumer Law. Gibson was required to pay $410,000 in penalties. Mortimer has also sat as a member of the Full Court of the Federal Court hearing appeals, and was a member of the bench that was critical of the approach of Judge Alexander Street in hearing applications by asylum seekers. In 2018 Mortimer presided over
an historic judgement resulting in an
Indigenous land use agreement, after a claim brought by
Kaurna elders in
Adelaide 18 years earlier. This was the first claim for a first land use agreement to be agreed to in any Australian capital city. On 25 November 2021, Justice Mortimer presided over a sitting at the
Federal Court in
Cairns that awarded of land on the eastern side of
Cape York Peninsula to the
Kuuku Ya'u and
Uutaalnganu peoples, in a
native title claim that was lodged seven years prior. On 31 March 2023 it was announced that she will be elevated to be Chief Justice of the Court from 7 April 2023. ==See also==