She is President of Justice, the law reform think tank, and is also director of the International Bar Association's Institute of Human Rights.

In 2024, Kennedy succeeded Lord Neuberger of Abbotsbury as Chair of the High Level Panel of Legal Experts on Media Freedom.

Among her many cases, Kennedy acted as junior counsel for child murderer Myra Hindley during her 1974 trial for plotting to escape from Holloway Prison.

In 2020, she worked with the Conservative MP Iain Duncan Smith and democracy activist Luke de Pulford to create the global pressure group Inter-Parliamentary Alliance on China.

[4] Kennedy regularly attends Mass and professes that her Roman Catholicism "remains very much part of who I am", even though she eschews its more traditional values.