The Pallium or Pall (derived, so far as the name is concerned, from the Roman pallium or palla, a woollen cloak) is an ecclesiastical vestment in the Roman Catholic Church, originally peculiar to the Pope, but for many centuries past bestowed by him on metropolitans and primates as a symbol of the jurisdiction delegated to them by the Holy See.

The pallium, in its present form, is a narrow band, "three fingers broad," woven of white lamb's wool, with a loop in the centre resting on the shoulders over the chasuble, and two dependent lappets, before and behind; so that when seen from front or back the ornament resembles the letter Y. It is decorated with six black crosses, one on each tail and four on the loop, is doubled on the left shoulder, and is garnished, back and front, with three jewelled gold pins. The two latter characteristics seem to be survivals of the time when the Roman pallium, was a simple scarf doubled and pinned on the left shoulder.

The Roman pallium is actually a vestigial omophorion; the omophorion is a wide band of cloth, much larger than the modern pallium, worn by all Eastern Orthodox bishops and Eastern Catholic bishops of the Byzantine Rite. The theory that explains its origin in connection with the figure of the Good Shepherd carrying the lamb on his shoulders, so common in early Christian art, is obviously an explanation a posteriori. The ceremonial connected with the preparation of the pallium and its bestowal upon the Pope at his coronation, however, suggests some such symbolism. The lambs whose wool is destined for the making of the pallia are solemnly presented at the altar by the nuns of the convent of Saint Agnes.

Presently, only the Pope and metropolitan archbishops wear the pallium, and a metropolitan has to receive the pallium before exercising his office in his ecclesiastical province, even if he was previously metropolitan elsewhere. Non-metropolitan archbishops do not wear the pallium unless they have special permission.