A liquid cartridge includes: a cartridge case defining therein a liquid storage chamber; a liquid supply portion; a circuit board; a plate member; and a residual-amount detecting portion. The residual-amount detecting portion is configured to change a state of incident light according to an amount of the liquid stored in the liquid storage chamber, and includes an optical access portion on which light traveling in a left-right direction is incident. The plate member is pivotally movable between: a first posture where a portion of the plate member is positioned upward relative to the optical access portion; and a second posture where the plate member is positioned downward relative to the optical access portion. The plate member in the first posture and the residual-amount detecting portion define a light transmissive region therebetween in the front-rear direction. The light transmissive region has a light transmittance greater than that of the plate member.