Calvarial bone flaps, either pedicled or free (with microvascular anastomoses), are primarily used for reconstruction of calvarial, midface/maxillary, and mandibular defects. Although the first description of pedicled calvarial bone flaps dates back to the late nineteenth century, more recently, these flaps have largely been replaced by other vascularized bone options, including the fibula and the scapula. However, calvarial bone flaps remain a reliable alternative for bony reconstruction of the calvarium and facial skeleton, especially when combined with overlying hair-bearing skin as osteocutaneous flaps for the reconstruction of bone and soft tissue in hair-bearing locations of the scalp or beard/mustache areas in male patients. In this chapter, we describe the history of these bone flaps, as well as their anatomy and steps for successful harvesting.