Kenneth Hayne was admitted as a barrister and solicitor of the Supreme Court of Victoria in 1971 and was appointed as a Queen's Counsel (QC) in 1984.

[4] Hayne has been described as being a part of a 'core' of judges during his time on the High Court, usually forming the majority, and often writing joint reasons with Justice William Gummow.

[5] One notable exception was Hayne's dissent in Thomas v Mowbray, where he joined Justice Michael Kirby in holding the Commonwealth's regime of interim control orders applied in respect of suspected terrorists to be unconstitutional.

[6][7] In December 2017 Hayne was appointed to head the Royal Commission into Misconduct in the Banking, Superannuation and Financial Services Industry.

[11][12][13] In August 2020, Hayne called upon all sides in politics to end "dialogue of the deaf", as in hyper-partisan conflict over climate change and over the Indigenous voice to parliament proposed in the Uluru Statement.