The dagger was first used during early Commando raids into occupied Europe but saw action in every theatre of World War II. US Rangers and Marines who had trained with the Commandos took their Fairbairn-Sykes daggers home which also influenced the development of American Special Forces daggers.

The dagger was first used during early Commando raids into occupied Europe but saw action in every theatre of World War II. US Rangers and Marines who had trained with the Commandos took their Fairbairn-Sykes daggers home which also influenced the development of American Special Forces daggers.