Sir William Seeds KCMG (27 June 1882 – 2 November 1973) was a British diplomat who served as ambassador to both the Soviet Union and Brazil.

After the death of Robert Seeds, his widow married in 1900 Sir William Squire Barker Kaye, CB, KC, Assistant Under-Secretary for Ireland.

In January 1922, having attended a rally at the Bürgerbräukeller, Seeds wrote one of the first British official reports on the Nazi Party in which he described Adolf Hitler as “a rabid Nationalist and anti-Semite”.

[11] In 1926–28 he was Envoy Extraordinary and Minister Plenipotentiary and Consul General to the Albanian Republic[12] under the rule of Zog I of Albania whom Seeds reported "is not the pallid tyrant trembling in his palace that some expect him to be".

[21] A tall and handsome man who charmed the ladies, Seeds was nevertheless known “not to suffer fools gladly, nor always sufficiently restrain his brilliant wit”.

Their eldest son, Robert Seeds[24](1914–1991), a Major in the Intelligence Corps (United Kingdom) who lost his left hand in 1941 whilst detonating a bomb for the Special Operations Executive,[25] was a university professor and journalist working in and for Saudi Arabia from 1959 until his death.