Myrmecia regularis is a species of ant endemic to Australia. A member of the genus Myrmecia in the subfamily Myrmeciinae, it was first described by American entomologist Walter Cecil Crawley in 1925. These ants are medium to large in size, measuring 10 to 20 millimetres (0.4 to 0.8 in), and they are bright brownish-red in colour. Queens and workers share similar morphological features, but they can be distinguished by the noticeable size difference. Males also look similar, but collected specimens are too damaged to be examined properly.