Megacephala martii is a species of ground beetle in the subfamily of Carabinae that was described by Perty in 1830. The species could be found in Santa Cruz, Bolivia and Paraguay. It can also be found in various cities of Brazil such as Goiás, Mato Grosso, and Sao Paulo. The female species are fully green coloured, while males are metallic-blue, with green pronotum. Both sexes have brown coloured legs and antennas.