Douglas Harvey Monro Gibson (born 8 August 1942) is a South African retired attorney, politician and diplomat who served as South Africa's ambassador to Thailand between 2008 and 2012. Previously, he had served as chief whip of the opposition from 1999 to 2007, as chairperson of the federal council of the Democratic Party between 1997 and 2000, and as a Member of the National Assembly of South Africa between 1994 and 2008.