Sir Arthur King Trethowan KCMG (14 September 1863 – 26 November 1937) was an Australian politician.
On 9 November 1886 he married Jane Alice Manifold, with whom he had eleven children.
Around 1898 he bought land at Berrigan, later expanding his interests to include property at Oaklands, Dubbo and the Upper Hunter.
In 1916 he was appointed to the New South Wales Legislative Council, where he served until his death at Dubbo in 1937.
This article about a National Party of Australia politician is a stub.