The armpit (or axilla) is the area on the human body directly under the area where the arm connects to the shoulder. Hair usually grows in the armpits of both males and females beginning in adolescence, though it is the norm in Western society for females to remove it. Also, armpits develop BO or body odor; for this, there is a wide variety of commercial deodorant and antiperspirant products.

Anatomically, the axilla is bounded anteriorly by the pectoralis major and minor muscles, posteriorly by subscapularis and the scapula, medially by the ribcage and by serratus anterior, and laterally by coracobrachialis and the short head of biceps brachii.