A liquid cartridge detachably attachable to an attachment section including a liquid supply needle, the liquid cartridge comprising: a housing having a liquid storage chamber configured to store liquid therein; a liquid supply tube defining an internal space therein and extending in an extending direction from the housing and having a distal end formed with an opening, the liquid supply tube being configured to provide communication between the liquid storage chamber and the liquid supply needle; a sealing member sealing the opening of the liquid supply tube, the sealing member having an inner peripheral surface defining a liquid supply hole extending in the extending direction; and a cap having an opening through which the liquid supply needle is inserted, the sealing member being interposed between the cap and the liquid supply tube in the extending direction, wherein the sealing member is elastically deformable, the sealing member comprising: a cylindrical portion defining an axis extending in the extending direction; a first protrusion protruding radially inward from the inner peripheral surface of the cylindrical portion, the first protrusion having a first protruding end defining a first sealing surface facing the axis, the first sealing surface being configured to contact an outer peripheral surface of the liquid supply needle; a second protrusion protruding radially outward from an outer peripheral surface of the cylindrical portion to have a second protruding end in a direction away from the axis, the second protruding end having a second sealing surface in contact with the distal end of the liquid supply tube; and a third protrusion protruding from the cylindrical portion in the extending direction along the axis to have a third protruding end in the extending direction, the third protrusion having a contacting surface inclined relative to the axis to face the axis, the contacting surface being in contact with the cap. a housing having a liquid storage chamber configured to store liquid therein; a liquid supply tube defining an internal space therein and extending in an extending direction from the housing and having a distal end formed with an opening, the liquid supply tube being configured to provide communication between the liquid storage chamber and the liquid supply needle; a sealing member sealing the opening of the liquid supply tube, the sealing member having an inner peripheral surface defining a liquid supply hole extending in the extending direction; and a cap having an opening through which the liquid supply needle is inserted, the sealing member being interposed between the cap and the liquid supply tube in the extending direction, wherein the sealing member is elastically deformable, the sealing member comprising: a cylindrical portion defining an axis extending in the extending direction; a first protrusion protruding radially inward from the inner peripheral surface of the cylindrical portion, the first protrusion having a first protruding end defining a first sealing surface facing the axis, the first sealing surface being configured to contact an outer peripheral surface of the liquid supply needle; a second protrusion protruding radially outward from an outer peripheral surface of the cylindrical portion to have a second protruding end in a direction away from the axis, the second protruding end having a second sealing surface in contact with the distal end of the liquid supply tube; and a third protrusion protruding from the cylindrical portion in the extending direction along the axis to have a third protruding end in the extending direction, the third protrusion having a contacting surface inclined relative to the axis to face the axis, the contacting surface being in contact with the cap. a cylindrical portion defining an axis extending in the extending direction; a first protrusion protruding radially inward from the inner peripheral surface of the cylindrical portion, the first protrusion having a first protruding end defining a first sealing surface facing the axis, the first sealing surface being configured to contact an outer peripheral surface of the liquid supply needle; a second protrusion protruding radially outward from an outer peripheral surface of the cylindrical portion to have a second protruding end in a direction away from the axis, the second protruding end having a second sealing surface in contact with the distal end of the liquid supply tube; and a third protrusion protruding from the cylindrical portion in the extending direction along the axis to have a third protruding end in the extending direction, the third protrusion having a contacting surface inclined relative to the axis to face the axis, the contacting surface being in contact with the cap.