Sir George Petre KCMG CB (4 September 1822 – 17 May 1905) was a British diplomat who was envoy to Argentina, Paraguay and Portugal.
He moved to Hanover in 1852, Paris in 1853, The Hague in 1855 and Naples in 1856, where he was chargé d'affaires from July 1856 when the ambassador, Sir William Temple, left due to illness, until October of that year when diplomatic relations with the Kingdom of the Two Sicilies were broken off.
In 1887 and 1889 the Foreign Secretary, Lord Salisbury, instructed Petre to protest at Portuguese attempts to extend their territories into Mashonaland and northwards to Lake Nyasa.
"A modus vivendi was agreed upon and signed by Lord Salisbury and the new Portuguese minister, Senhor Luiz de Soveral, on 14 November 1890, by which Portugal granted free transit over the waterways of the Zambesi, Shire and Pungwe rivers and a satisfactory settlement was finally placed on record in the convention signed by Petre and the Portuguese minister for foreign affairs on 11 June 1891.
Petre's naturally calm and conciliatory disposition and the excellent personal relations which he succeeded in maintaining with the Portuguese ministers did much to keep the discussions on a friendly basis and to procure acceptance of the British demands.