A fluid injector including an injector housing with at least one syringe port for receiving a syringe, and a locking mechanism associated with the at least one syringe port for securing the syringe within the at least one syringe port. The locking mechanism is configured for engaging at least one syringe retaining member of the syringe to releasably lock the syringe within the at least one syringe port. The at least one syringe retaining member rotationally guides the syringe into self-orienting alignment with the locking mechanism and is rotated by the locking mechanism into fully locked position after axial installation of the syringe into the at least one syringe port. The locking mechanism also axially ejects the syringe from the locking mechanism upon rotation of the syringe during removal.