Red foxes are usually together in pairs or small groups consisting of families, such as a mated pair and their young, or a male with several females having kinship ties.
The word "fox" comes from Old English, which derived from Proto-Germanic *fuhsaz. vulpes by its slightly smaller size, distinctly smaller teeth, and widely spaced premolars. It is ruddy to grey-brown above and darker on the back of the neck. The hindquarters are frosted with white and the tail is clear grey in colour.
Compare with West Frisian foks, Dutch vos, and German Fuchs. Red foxes present in Britain (and therefore Australia) are usually ascribed to this subspecies, though many populations there display a great degree of tooth compaction not present in continental European populations. Their skulls are fairly narrow and elongated, with small braincases. Sexual dimorphism of the skull is more pronounced than in corsac foxes, with female red foxes tending to have smaller skulls than males, with wider nasal regions and hard palates, as well as having larger canines.
The remaining lower surface of the body is dark, brown or reddish.
The upper parts of the limbs are rusty reddish, while the paws are black.
The bushy tail also forms the basis for the fox's Welsh name, llwynog, literally 'bushy', from llwyn 'bush'. A large subspecies measuring 70–90 cm in length and weighing 5–10 kg, the maximum length of the skull for males is 163.2 mm. They display significant individual, sexual, age and geographical variation in size.