The subscapularis (latin: musculus subscapularis) is a flat, triangular muscle of the shoulder girdle.
The subscapularis originates from the subscapular fossa on the costal surface of the scapula.
The subscapularis fills the subscapular fossa, passes laterally upwards and inserts to the lesser tubercle of the humerus.
The subscapularis is one of the rotator cuff muscles that stabilizes the shoulder and provides adduction and internal rotation of the upper arm.
The subscapularis is innervated by the subscapular nerve.