This chapter examines references to the breath of God in the writings of medieval women mystics including Hildegard of Bingen, Hadewijch of Antwerp, Mechthild of Magdeburg, Marguerite Porete, Angela of Foligno, and Julian of Norwich. In Christian mystical writings, the Holy Spirit is often imaged as the breath or wind that blows through creation, vivifying humans, and instructing and inspiring them with its gifts. Shaped by the biblical culture in which they lived, medieval women’s writings describe human breath as created by God and shared with other elements of creation. They name the Holy Spirit as the divine breath that appears in winged form and flowed through them. And they cultivate their breath through shared spiritual practices of preaching, singing, and writing. These themes of breath as created, divine, and cultivated suggest a medieval respiratory theology with elements of theological anthropology, theology of creation, and practical theology. Placing these writings in biblical and historical context, this chapter describes how women writers interpret the human breath as a divine gift and expression of love through the work of the Holy Spirit. Reading these breath-filled writings today reminds us to share the air through practices of breathing together, such as singing, that respond constructively to contemporary crises, and create a breath-filled conspiracy of love.