An assembly comprising a fluid dispenser and a filling cartridge (C; C'), the fluid dispenser comprising: • a base part that is mounted on a fluid reservoir, the base part including a dip tube and a cup in which there is formed an injection orifice that is connected to the dip tube, the cup being provided with a piston, the base part also including a fastener bushing, and • a removable member that is mounted on the base part in removable manner along a slide axis, the removable member comprising a grip appendage, a tubular part that is suitable for sliding along a slide axis in leaktight manner against the piston over a leaktight axial stroke and an applicator that is capable of retaining a dose of fluid coming from the injection orifice by suction that is generated by the leaktight sliding of the tubular part against the piston, the applicator including an extraction and application space that is formed in the tube, the fluid being injected into the extraction and application space through the dip tube and the injection orifice, the removable member also comprising a fastener ring that is fastened in removable manner on the fastener bushing, the filling cartridge (C; C') comprising a container containing fluid, and a connector endpiece (6; 6') for connecting to the fluid dispenser for passing the fluid from the container to the fluid reservoir, the connector endpiece (6; 6') comprising: • a junction appendage (60; 60') for the container, • an outer fastener ring (64; 34) that is adapted to co-operate with the fluid dispenser so as to fasten the filling cartridge (C; C') in removable manner on the fluid dispenser (D, and • an inner sleeve (61; 32') that extends inside the outer fastener ring (64; 34), the inner sleeve (61; 32') internally forming a fluid passage that puts the inside of the container into communication with the outside, the inner sleeve (61; 32') externally forming a leaktight sliding-contact wall that is adapted to come into radial leaktight sliding contact with the fluid dispenser so as to achieve temporary sealing between the filling cartridge (C; C') and the fluid dispenser, the connector endpiece (6; 6') of the filling cartridge (C; C') being mounted in removable manner on the base part with the inner sleeve (61; 32') penetrating into the cup, the leaktight sliding-contact wall is mounted in radial leaktight sliding contact with the piston and the outer fastener ring (64; 34) in engagement with the fastener bushing. • a base part that is mounted on a fluid reservoir, the base part including a dip tube and a cup in which there is formed an injection orifice that is connected to the dip tube, the cup being provided with a piston, the base part also including a fastener bushing, and • a removable member that is mounted on the base part in removable manner along a slide axis, the removable member comprising a grip appendage, a tubular part that is suitable for sliding along a slide axis in leaktight manner against the piston over a leaktight axial stroke and an applicator that is capable of retaining a dose of fluid coming from the injection orifice by suction that is generated by the leaktight sliding of the tubular part against the piston, the applicator including an extraction and application space that is formed in the tube, the fluid being injected into the extraction and application space through the dip tube and the injection orifice, the removable member also comprising a fastener ring that is fastened in removable manner on the fastener bushing, • a junction appendage (60; 60') for the container, • an outer fastener ring (64; 34) that is adapted to co-operate with the fluid dispenser so as to fasten the filling cartridge (C; C') in removable manner on the fluid dispenser (D, and • an inner sleeve (61; 32') that extends inside the outer fastener ring (64; 34), the inner sleeve (61; 32') internally forming a fluid passage that puts the inside of the container into communication with the outside, the inner sleeve (61; 32') externally forming a leaktight sliding-contact wall that is adapted to come into radial leaktight sliding contact with the fluid dispenser so as to achieve temporary sealing between the filling cartridge (C; C') and the fluid dispenser,