A catheter assembly (10A) includes: a catheter (12)； a catheter hub (14) connected to the catheter (12)； an inner needle (16) removably inserted into the catheter (12)； a needle hub (18) connected to the inner needle (16)； and a deflection suppressing member (20) that suppresses deflection of the inner needle (16) by supporting the inner needle (16) via the catheter (12) on more toward the distal end side than the catheter hub (14). The deflection suppressing member (20) is supported so as to be movable relative to the needle hub (18) in the axial direction.
