An inkjet printer head including: (a) a front head unit having (a-i) an outside surface which is to be opposed to a print media, (a-ii) an inside surface opposite to the outside surface, (a-iii) a plurality of nozzles opening in the outside surface and arranged in row, and (a-iv) an ink inlet opening in the inside surface; (b) an ink-channel defining unit supplying an ink into the front head unit through the ink inlet; (c) a head holder holding the front head unit; and (d) a reinforcement member fixed to the inside surface of the front head unit. The front head unit and the head holder are fixed to each other, with the reinforcement member being interposed therebetween. The ink-channel defining unit is fixed to one of opposite side surfaces of the reinforcement member that is remote from the front head unit. Also disclosed is an inkjet printer including the above-described inkjet printer head, a carriage, a heat dissipater and a bubble discharger, wherein the heat dissipater, bubble discharger and front head unit are mounted on the carriage, and are arranged in a direction of movement of the carriage.