Operation Musketeer was the Anglo-French plan for the invasion of the Suez canal zone to capture the Suez Canal during the Suez Crisis in 1956. The operation had initially been given the codename Operation Hamilcar, but this name was quickly dropped when it was found that the British were painting an air recognition letter H on their vehicles, while the French, who spelled Hamilcar differently, were painting an A. Musketeer was chosen as a replacement because it started with M in both languages. Israel, which invaded the Sinai peninsula, had the additional objectives of opening the Straits of Tiran and halting fedayeen incursions into Israel. The Anglo-French military operation was originally planned for early September, but the necessity of coordination with Israel delayed it until early November. However, on 10 September British and French politicians and Chiefs of the General Staff agreed to adopt General Charles Keightley's alterations to the military plans with the intention of reducing Egyptian civilian casualties. The new plan, renamed Musketeer Revise, provided the basis of the actual Suez operation.

General Sir Charles Frederic Keightley, was a senior British Army officer who served during and following the Second World War. After serving with distinction during the Second World War – becoming, in 1944, the youngest corps commander in the British Army – he had a distinguished postwar career and was the Governor of Gibraltar from 1958 to 1962.