A new species of the rare ant genus Metapone , Metapone murphyi sp. nov., is described based on museum material consisting of a single nest series (workers, queens, and males) collected from a decayed coconut palm stump on Pulau Sakra, previously an offshore island south of mainland Singapore. Workers can be distinguished from other named congeners mainly by the following characters: 1) subpetiolar lamella subrectangular; 2) short median longitudinal ventral subpetiolar edge and roundly obtuse posteroventral subpetiolar angle; 3) outer margin of posterior subpetiolar face in posteroventral view forming a continuous, U-shaped, translucent, laminate carina; and 4) petiole subtrapezoidal in dorsal view with extended blunt tooth-like posterolateral corners. Detailed description and illustrations of male genitalia of the genus are given for the first time. The key to Asian species of Metapone is updated to include the new species.