The mandible pronunciation (from Latin mandibula, "jawbone") or inferior maxillary bone forms the lower jaw and holds the lower teeth in place. The term "mandible" also refers to both the upper and lower sections of the beaks of birds; in this case the "lower mandible" corresponds to the mandible of humans, while the "upper mandible" is functionally equivalent to the human maxilla but mainly consists of the premaxillary bones. Conversely, in bony fish for example, the lower jaw may be termed "lower maxilla".

The mandible consists of:

Inferior alveolar nerve, branch of the mandibular division of Trigeminal (V) nerve, enters the mandibular foramen and runs forward in the mandibular canal, supplying sensation to the teeth. At the mental foramen the nerve divides into two terminal branches: incisive and mental nerves. The incisive nerve runs forward in the mandible and supplies the anterior teeth. The mental nerve exits the mental foramen and supplies sensation to the lower lip.

The mandible articulates with the two temporal bones at the temporomandibular joints.