William George Foster, GC, MC, DCM (12 December 1880 – 13 September 1942) was a British Home Guard officer who was posthumously awarded the George Cross for the heroism he displayed on 13 September 1942 when his prompt actions saved his comrades after a grenade accident during training in Ashley Hill, Clarendon Park near Salisbury in Wiltshire. In protecting his comrades from death or severe injury his own life was lost.