Colonel Sir James Hayes Sadler KCMG CB FRGS (21 May 1827 – 9 January 1910) was a British diplomat and civil servant.

[2] In 1854 Sadler was commissioned into the Royal Sussex Militia Artillery, a newly formed part-time home defence unit of the Royal Artillery (RA).

(It was retitled the 3rd Brigade, Cinque Ports Division, RA, in 1882 and Sussex Artillery (Eastern Division) RA in 1889, before becoming the Sussex Royal Garrison Artillery (Militia) in 1902.).

[5] After serving as Consul-General in Valparaiso, Chile from 1895 he was made a Knight Commander of the Order of St Michael and St George (KCMG) in the 1899 New Year Honours.

Their son, also named Sir James Hayes Sadler (1851–1922) was a colonial administrator, who also a military man and was also awarded the KCMG.