Operation Ambassador was an operation carried out by British Commandos on 14–15 July 1940 within the context of the Second World War. It was the second raid by the newly formed British Commandos and was focused upon the German-occupied Channel island of Guernsey.

The Commandos, also known as the British Commandos, were formed during the Second World War in June 1940, following a request from Winston Churchill, for special forces that could carry out raids against German-occupied Europe. Initially drawn from within the British Army from soldiers who volunteered for the Special Service Brigade, the Commandos' ranks would eventually be filled by members of all branches of the British Armed Forces and a number of foreign volunteers from German-occupied countries. By the end of the war 25,000 men had passed through the Commando course at Achnacarry. This total includes not only the British volunteers, but volunteers from Greece, France, Belgium, Netherlands, Canada, Norway and Poland. The United States Army Rangers and US Marine Corps Raiders, Portuguese Fuzileiros Portuguese Marine Corps were modelled on the Commandos.