Calosoma retusum is a beetle of the family Carabidae.

Calosoma retusum reaches about 25–32 millimetres (0.98–1.26 in) in length.

This species usually has a bright metallic dark green or bronze green coloration, sometime with bluish reflections.

These beetles are voracious consumer of caterpillars, so they are considered beneficial insects for the agriculture.

[1] This species occurs in southern Brazil, Uruguay, Argentina, Bolivia and Peru.