Edward Henry St John QC (pr: Sinj'n) (15 August 1916 – 24 October 1994) was a prominent Australian barrister, anti-nuclear activist and Liberal politician in the 1960s.

[2] His father was an Anglican minister and the family had a history of involvement with the church, with his grandfather being a nephew of Ambrose St John.

[2] St John became a barrister in 1940 and served in the 2nd AIF in Australia, the Middle East and the New Guinea campaign between 1940 and 1945 during World War II.

In November 1966 St John was elected to the House of Representatives as the Liberal member for the safe seat of Warringah.

Instead, he criticised, in forthright terms, the conduct and findings of the Royal Commission into the Voyager disaster, calling for a second inquiry.

In a debate on the new General Dynamics F-111 aircraft the Minister for Air, Gordon Freeth, said of St John: On 20 March 1969, he embarrassed his party by criticising the behaviour of Prime Minister John Gorton, claiming that he had offended American ambassador Crook by turning up at 1 am at the American embassy, after a late press-gallery dinner, with journalist Geraldine Willesee, the 19-year-old daughter of Labor Senator Don Willesee.

[8][9] Labor Senator Lionel Murphy sent a message to the House suggesting that St John's comments were an inappropriate breach of the Prime Minister's privacy.

[11][12] Ms Willesee issued a statutory declaration stating that she talked with Gorton on Vietnam and politics, the two were always in mixed company throughout the morning.

[13] Gorton's wife Bettina supported her husband by sending a poem to the press gallery, referring to St John as "the member with the Serpent's tongue".

Despite this conservatism, he set up the International Defence and Aid Fund for Southern Africa for victims of apartheid;[1] and his election to parliament had been firmly opposed by the Australian League of Rights.

After leaving politics for himself he supported Peter Garrett's Nuclear Disarmament Party candidature for the Australian Senate in 1984, which almost succeeded.

[1][23] From 1985 St John began writing his major work, an anti-nuclear book Judgment at Hiroshima, with some research assistance from Elizabeth Handsley[23] but died before publication.

His widow Valerie released the English version two years later with copies distributed to research libraries in Australia and overseas.