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 provided on the rings. The spacer comprises opposite first and second portions 11, 12 facing one another and at least a first lateral portion 13 extending transversally between the first and second portions and connected to the portions. The first and second portions and the first lateral portion delimit at least partly a pocket 14 laterally open on the side opposite to the lateral portion 13 and configured to receive at least a contact roller. The first and second portions each comprise an inner contact surface 11a, 12a with an end face of the roller. The spacer further comprises at least one reinforcing beam 16, 17 extending transversally between the first and second portions and connected to the portions.