A catheter assembly comprises: a catheter； a catheter hub fixed to a proximal end portion of the catheter； an inner needle disposed inside the catheter； and a housing； wherein a distal end of the housing comprises a portion configured to support the inner needle via the catheter； wherein, when the catheter assembly is in an initial state in which a distal end of the inner needle protrudes from a distal end of the catheter, the housing accommodates the catheter hub； and wherein the catheter hub is configured to rotate with respect to the inner needle and the housing when accommodated inside the housing.
