In anatomy, a suture is a line marking the junction between two body parts. Cranial sutures are the joints between the bones of the skull. A suture is said to be serrated when it is formed by the union of two edges of bone with projections and indentations. The coronal, sagittal, and lambdoidal sutures are of this kind. A suture is said to be squamous when it is formed by the overlapping of the beveled (or scale-like) edges of two contiguous bones.

Sutures are also found in various plant structures, including beans, peas, and carpels. In insects, sutures (Latin sutura, "a seam") exist at the junctions between plates of hardened cuticle of exoskeleton. In surgery, a suture is a sewn-together wound.

In surgery, a suture is any of a variety of methods of sewing up a wound, so as to maintain the opposed surfaces in contact.