The appearance of the Druid is known to us from two main sources: Greco-Roman writings and medieval Irish tradition. There is also some evidence from Irish and Scottish folklore. Druids wore white tunics, which in early Ireland were knee-length. The concept of their wearing full white robes was formed from misunderstandings of the English translations of Pliny, who mentioned candida vesta, "white garments," in reference to gathering mistletoe. He did not, however, say white robes, but white garments or white clothing. He was probably describing a tunic and perhaps also a cloak. This formed a part of the clothing worn by the chief bard in Highland Scottish inaugurations of clan chiefs. Records of both Irish and Scot traditions also mention a rod or scepter of straight white wood gilded with metal, and this has been confirmed by archaeology. The rod or scepter was carried as a badge of office.
Records of Irish tradition also speak of bird-feather cloaks of the filídh, cloaks of grey or white bull-hide of the Druids, and bards wearing plaited or braided hair. Druids were often described as bald (many had the nickname Mael??"Old Irish for "bald"). The bald head was probably a Druidic tonsure, presumably the same kind of partially-shaven head used by later Irish clerics and condemned by the Roman church as non-conformist. This kind of tonsure is made by shaving the hair from ear to ear, along to the front hairline. This gives the appearance of a receding hairline or of a very high forehead. It is interesting to note that Indian Brahmans have a very similar tonsure!
One Druid named Mogh Ruith was described as wearing a speckled bird headdress; perhaps it was a sort of bird-hat or helmet with fluttering wings. It is true that Druids used gilded bronze sickles for cutting sacred healing herbs (e.g. Pliny’s report of the mistletoe gathering), but there is no tradition of them carrying the sickles around as emblem of their office.
There is no mention of Druids going either bearded, moustached or clean-shaven. It was a typical Gaulish fashion in ancient times for men to sport a moustache. Gallo-Roman men appear in sculptural portraits with moustaches and long sideburns, which were considered barbaric by Roman tastes. Early Celts preferred longer hair to the Roman styles; later the Roman fashion prevailed in Gaul for a few centuries, until Germanic fashions came with the invasions of Burgundians, Franks and Goths.
Celtic women dressed in ankle-length, pleated frocks or pleated ankle-length skirts with tunics. Often an attractive white apron was tied to the shoulders and covered the entire outfit. A cloak or tartan shawl has been the Celtic fashion from ancient times to the present day. A red skirt was traditionally worn by women in the Gaeltachts. One description of Druids fighting the Romans at Anglesey mentions priestesses wearing black. Presumably this was because they were cursing the enemy, but it could also have been a representational image of the war-goddess Catubodua or Badb Catha, the "war-crow." The cloak/shawl of the bendrvi or ueleda was drawn over the head when practicing ceremonies or offerings. Celtic women wore plaited or braided hair in many different styles??"pigtails, rings, buns, etc.
Both Celtic men and women wore shoes of rough hide and the breccan, or tartan wool fabrics. Breccan style fabric was worn all over the Celtic world, though today it is associated chiefly with Scotland.
All Celtic nobility wore the maniacis (mah-nyah-kiss), or collar, which was often an open-front neckring made of tubing or twisted silver, bronze or gold. The maniacis collar, or "torque," was associated with one’s touta or sliocht (tribe).
The tricoros or "triskele," an ancient solar symbol representing the divine presence of Nemos, or heaven, has been found on a pre-Christian bracteate (medallion) in Ireland.