Dorcus titanus, the giant stag beetle, is a beetle of the family Lucanidae. It was described by Jean Baptiste Boisduval in 1835.
Males measure 32.0–111.3 millimetres (1.26–4.38 in) including mandibles; females 36.5–54 millimetres (1.44–2.13 in). It has an elongated, somewhat flat body dull black with blackish antennae and legs. Male’s antler-like jaws have small teeth along inner edge and a pair of big teeth toward the bottom, and are forked at end. Head of a large male reaches nearly the length of its prothorax and abdomen combined.