'Bonus' was a British unrealised plan for an amphibious operation against the Vichy French island of Madagascar, in the Indian Ocean off the eastern coast of Africa, later developed into 'Ironclad' (December 1941/30 April 1942).

After the failure of the joint British and Free French 'Menace' against Dakar, Prime Minister Winston Churchill felt that any other undertaking against Vichy France might suffer the same fate if attempted on the same joint basis, and therefore ordered the preparation of 'Bonus' as a British and commonwealth effort with US support but no Free French involvement. Churchill’s directive therefore envisaged the use of Rear Admiral E. N. Syfret’s Force 'H', whose place at Gibraltar would be assumed by a US Navy task force, the retention of the 4,000-man force proposed by Admiral the Lord Louis Mountbatten as the nucleus of the new plan using Major General R. M. Sturges’s Force 121. 'Bonus' was to be launched no later than 30 April 1942.