This paper seeks to unpack the complex spatialities of UK airspace, looking beyond traditional civil aviation classifications to focus specifically on the spaces used by military aviation in the UK context. It argues that UK national sovereign airspace should not be viewed as a single homogenous entity, but instead must be reconceptualised as a plethora of multiple, vertically and horizontally, overlapping airspaces that can be activated or deactivated according to need. The paper employs a performativity-based framework that highlights specifically how these spaces are identified and named, to illustrate how these multiple military airspaces are actively performed. Within this it focuses on analysing the citational and iterative actions of professional airspace managers working within the UK Civil Aviation Authority and Royal Air Force. The paper makes extensive use of documentary sources and interviews with key personnel to illustrate how the airspaces above the UK are brought into being through the actions of these actors and how these operations can be seen as part of a wider enactment of militarism’s control over space.