The spacer is adapted for a rolling bearing comprising an inner ring, an outer ring and at least one row of contact rollers disposed between raceways and guiding surfaces provided on the rings. The spacer comprises opposite inner and outer portions facing one another and at least a first lateral portion extending transversally between the inner and outer portions and connected to the portions. The inner and outer portions and the first lateral portion delimit at least partly a pocket configured to receive at least a contact roller. The inner and outer portions each comprise at least a protruding means extending outwards and having a contact surface with one of the inner and outer rings.