Dame Kate Thirlwall was called to the Bar in 1982 and appointed as an Assistant Recorder of the Crown Court in 1998. She became a QC (now KC) in 1999 and was appointed as a Recorder in 2000. She became a bencher of Middle Temple in 2008.
In 2010 Lady Justice Thirlwall was appointed as a High Court Judge and assigned to the Queen’s Bench Division (now King’s Bench Division). Between 2011 and 2015, she served as the Presiding Judge of the Midland Circuit. During that time she was Chair of Magistrates Training at the Judicial College. In 2016 she was appointed to the Sentencing Council.
She was appointed a Lady Justice of the Court of Appeal in February 2017.
Lady Justice Thirlwall was appointed Deputy Senior Presiding Judge for England and Wales, with effect from 10 October 2017. She served as Senior Presiding Judge from 1 January 2020 until 30 September 2021.