Spheres of influence remain one of the most pervasive phenomena in the practice and history of international relations, yet only rarely have they been taken up analytically. To bring conceptual and discursive clarity, this article advances two arguments. First, it argues that spheres of influence are not a distinct form of hierarchy in international relations, but rather practices of control and exclusion that can be found within any ideal-type hierarchy. Second, these hierarchical practices are generally underspecified by those invoking the term. Different theoretical perspectives on international relations offer highly divergent ways of understanding control and exclusion, and all do so with plausible empirical mooring. Spheres of influence do not themselves denote a form of governance even if it does a form of order construction and maintenance. Any given empire, hegemonic order, or alliance may also be a sphere of influence depending on the practices that occur; the key is not to identify whether particular hierarchical traits are dispositive of one of these relational structures, but rather whether, and the extent to which, assertions of control and exclusion define the hierarchy.