Though Calvin is averse to theological speculation, he is the first to claim that Christ is Mediator and Head of Angels. This often-overlooked office is present consistently throughout the various editions of the Institutes and can be found in his treatises, commentaries, catechism, and various sermons. This paper argues that Christ's mediation of angels is a form of ontological mediation that serves as the logical foundation for his redemptive mediation of the Elect. Sin is an intensification of a preexisting problem that requires the Son to be the medius and Mediator between God and creation because of his unique position in the Trinitarian taxis as the begotten one. This overlooked office places Calvin's theology of mediation in a greater cosmic context where the triune God is uniting all things to himself typified in the angels and the Elect.