To provide a sealing unit for a roll neck of a rolling mill having a self-lubricating property, which dispenses with an external supply of lubricant of a seal.

In the sealing unit 5 in which the sealing unit is assembled between an axle box 3 of a bearing unit 2 rotatably supporting a roll neck 1 and an outer periphery of the roll neck, its outer diameter side is fixed in the axle box, and its inner diameter side is slid with the outer periphery of the roll neck, the sealing unit comprises a circular inner seal 6, a circular outer seal 7, and a lubricant supply member 16 retained between the inner seal and the outer seal at a view from the inside of the axle box to the outside. The lubricant supply member has a lubricant self-supplying property naturally exuding due to a temperature rise resulting from heat-transfer of frictional heat caused by a sliding contact with the roll neck via the seal.