Sutures are fibrous joints in the vertebrate skull. They consist of two bone ends and intervening fibrous tissue which differentiates from embryonic mesenchyme. Sutures are not merely articulations between bones they are primary sites of osteogenesis mediating much of the growth of the face and skull vault. In this chapter the development of sutures will be described including the origin of sutural tissues, the determinants of suture location, and suture morphology. Also, the main functions of sutures will be explained.