A liquid cartridge (30; 230) comprising: in an operational posture of the liquid cartridge (30, 230), a cartridge casing having a liquid storage chamber configured to store a liquid therein, the cartridge casing having an inner surface (37A, 38A, 40A, 41A, 48A, 45A; 240A, 241A, 248A, 245A) defining the liquid storage chamber; a liquid supply portion for supplying the liquid stored in the liquid storage chamber to an outside of the liquid cartridge (30; 230), the liquid supply portion having a liquid supply hole (35, 71) extending in a frontward direction from the liquid storage chamber to an outside, the frontward direction being perpendicular to a gravitational direction; a front wall (40, 49; 240) at which the liquid supply portion is disposed; a rear wall (41; 241) spaced away from the front wall in a rearward direction opposite to the frontward direction; a bottom wall (42, 45, 48; 242, 245, 248) extending in a front-rear direction (51, 52) between the front wall and the rear wall; a first side wall extending in an up-down direction (53, 54) and the front-rear direction, the first side wall being connected to the front wall, the rear wall, and the bottom wall, the up-down direction being parallel to the gravitational direction; and a second side wall facing the first side wall and extending in the front-rear direction and the up-down direction, the second side wall being connected to the front wall, the rear wall, and the bottom wall, characterised in that the inner surface includes a side surface (37A, 38A, 40A, 41A; 240A, 241A) and a bottom surface (48A, 45A; 248A, 245A), the bottom surface having a curved region (115A, 116A, 119A, 122A) connected to the side surface, the bottom surface has a lowermost portion constituted by the curved region (115A, 116A, 119A) and the lowermost portion is positioned at a widthwise centre region of the bottom surface in a widthwise direction (55, 56) perpendicular to the gravitational direction and the frontward direction, the side surface (37A, 38A, 40A, 41A; 240A, 241A) is provided by at least one of the front wall, the rear wall, the first side wall, and the second side wall, and the bottom surface (48A, 45A; 248A, 245A) is provided by the bottom wall (48, 45), and in that, in the operational posture of the liquid cartridge, the liquid supply hole (35, 71) is positioned downward relative to a portion (48; 248) of the bottom wall (42, 45, 48; 242, 245, 248), and the bottom surface (45A; 245A) has a communication opening in communication with the liquid supply hole (35, 71), the bottom surface being sloped downward toward the communication opening in the operational posture of the liquid cartridge. in an operational posture of the liquid cartridge (30, 230), a cartridge casing having a liquid storage chamber configured to store a liquid therein, the cartridge casing having an inner surface (37A, 38A, 40A, 41A, 48A, 45A; 240A, 241A, 248A, 245A) defining the liquid storage chamber; a liquid supply portion for supplying the liquid stored in the liquid storage chamber to an outside of the liquid cartridge (30; 230), the liquid supply portion having a liquid supply hole (35, 71) extending in a frontward direction from the liquid storage chamber to an outside, the frontward direction being perpendicular to a gravitational direction; a front wall (40, 49; 240) at which the liquid supply portion is disposed; a rear wall (41; 241) spaced away from the front wall in a rearward direction opposite to the frontward direction; a bottom wall (42, 45, 48; 242, 245, 248) extending in a front-rear direction (51, 52) between the front wall and the rear wall; a first side wall extending in an up-down direction (53, 54) and the front-rear direction, the first side wall being connected to the front wall, the rear wall, and the bottom wall, the up-down direction being parallel to the gravitational direction; and a second side wall facing the first side wall and extending in the front-rear direction and the up-down direction, the second side wall being connected to the front wall, the rear wall, and the bottom wall, characterised in that the inner surface includes a side surface (37A, 38A, 40A, 41A; 240A, 241A) and a bottom surface (48A, 45A; 248A, 245A), the bottom surface having a curved region (115A, 116A, 119A, 122A) connected to the side surface, the bottom surface has a lowermost portion constituted by the curved region (115A, 116A, 119A) and the lowermost portion is positioned at a widthwise centre region of the bottom surface in a widthwise direction (55, 56) perpendicular to the gravitational direction and the frontward direction, the side surface (37A, 38A, 40A, 41A; 240A, 241A) is provided by at least one of the front wall, the rear wall, the first side wall, and the second side wall, and the bottom surface (48A, 45A; 248A, 245A) is provided by the bottom wall (48, 45), and in that, in the operational posture of the liquid cartridge, the liquid supply hole (35, 71) is positioned downward relative to a portion (48; 248) of the bottom wall (42, 45, 48; 242, 245, 248), and the bottom surface (45A; 245A) has a communication opening in communication with the liquid supply hole (35, 71), the bottom surface being sloped downward toward the communication opening in the operational posture of the liquid cartridge.