[1] He was a member of the British fencing team (sabre) from 1977 to 1980[2] and was selected to compete at the 1980 Summer Olympics in Moscow,[3] but joined the boycott in protest against the 1979 Soviet invasion of Afghanistan.

[10] In October 2016 Etherton was one of the three judges forming the divisional court of the High Court in proceedings concerning the use of the royal prerogative for the issue of notification in accordance with Article 50 of the Treaty on European Union (the Lisbon Treaty) (Santos and Miller, Applicants -v- Secretary of State for Exiting the European Union, Respondent).

In June 2019, Etherton, Sir Stephen Irwin and Sir Rabinder Singh found that ministers had breached British law when they "made no concluded assessments of whether the Saudi-led coalition had committed violations of international humanitarian law in the past, during the Yemen conflict, and made no attempt to do so.

[18] In May 2022, Lord Etherton was appointed by the Government to carry out an independent review of the treatment of LGBT military personnel between 1967 and 2000.

In the 2024 Birthday Honours, Etherton was appointed Knight Grand Cross of the Order of the British Empire (GBE) for services to LGBT veterans.