A bearing structure includes: a ball bearing disposed in a bearing hole formed in a housing of a turbocharger, the ball bearing having an outer ring formed with a damper portion on an outer circumferential surface thereof; an opposed member fixed to the housing, the opposed member opposed to the outer ring in an axial direction of a shaft; a protruding portion formed on one of the outer ring and the opposed member, the protruding portion protruding toward another one of the outer ring and the opposed member; and a regulating portion formed on the other one of the outer ring and the opposed member, the regulating portion opposed to the protruding portion in a rotation direction of the shaft.