A syringe assembly includes: a syringe barrel including, at a distal end thereof, a cylindrical portion including a female luer to which a male luer is connectable； and a cap attached to the syringe barrel, the cap including: a cylindrical cap cover, and a plug fixed inside the cap cover, the plug sealing an opening of the cylindrical portion in a liquid-tight manner. The cap cover includes: a cylindrical body to which the plug is fixed, covering the cylindrical portion； a locking portion located on a proximal end side of the cylindrical body, and connecting portions connecting the cylindrical body and the locking portion in a breakable manner. The cylindrical portion includes, at an outer peripheral surface thereof, at least one protruding portion that restricts movement of the locking portion in a distal end direction with respect to the cylindrical portion.
