To provide a sealing device of a rolling bearing which effectively discharges a foreign material entered between a slinger and a seal to prevent it from being retained therebetween.

A sealing device of a rolling bearing includes a seal 20 which is fixed at an outer ring 14 and which rotates with the outer ring 14 and a slinger 30 which is fixed at an inner ring 12 on an outer side of a bearing of the seal 20, wherein a circular gap formed between the seal 20 and the slinger 30 is formed outside of the bearing on a radial outer side of the slinger 30 to configure a labyrinth R, and a projection 33 is formed on an inner side of the bearing of the slinger 30.