Monomorium denticulatum is a species of ant in the subfamily Myrmicinae. It known from Chile and Argentina. Like M. bidentatum it was first described from Valdivia, Chile.
Workers are 3 mm long, yellowish red, with brown head, petiole and abdomen. Females are 4 mm long and brownish black, with only the most distal tarsal elements and the tip of the abdomen reddish yellow.