A collapsible bottle defining a variable volume internal compartment for containing a fluid to be dispensed from a fluid dispenser, the collapsible bottle comprising: a first exterior wall; a second exterior wall; a third exterior wall; and a neck that extends along an axis away from the third exterior wall, the neck having an opening in fluid communication with the internal compartment; wherein the internal compartment contains an initial volume of the fluid when the collapsible bottle is in an initial configuration; wherein, as the fluid is dispensed from the collapsible bottle, the collapsible bottle deforms from the initial configuration towards a collapsed configuration, the internal compartment containing a smaller volume of the fluid when in the collapsed configuration than when in the initial configuration; wherein the first exterior wall is thinner than the second exterior wall; wherein the first exterior wall is further from the axis than the second exterior wall is from the axis when the collapsible bottle is in the initial configuration; and wherein the first exterior wall moves towards the axis as the collapsible bottle deforms from the initial configuration towards the collapsed configuration; wherein the first exterior wall and the second exterior wall are each intersected by a first plane that contains the axis; wherein the collapsible bottle has a fourth exterior wall and a fifth exterior wall that are each intersected by a second plane that contains the axis, the second plane being perpendicular to the first plane; wherein the collapsible bottle has a sixth exterior wall that is intersected by the axis; and characterized in that the fourth exterior wall, the fifth exterior wall, and the sixth exterior wall have a reinforcement structure that resists deformation of the fourth exterior wall, the fifth exterior wall, and the sixth exterior wall as the collapsible bottle deforms from the initial configuration towards the collapsed configuration. a first exterior wall; a second exterior wall; a third exterior wall; and a neck that extends along an axis away from the third exterior wall, the neck having an opening in fluid communication with the internal compartment; wherein the internal compartment contains an initial volume of the fluid when the collapsible bottle is in an initial configuration; wherein, as the fluid is dispensed from the collapsible bottle, the collapsible bottle deforms from the initial configuration towards a collapsed configuration, the internal compartment containing a smaller volume of the fluid when in the collapsed configuration than when in the initial configuration; wherein the first exterior wall is thinner than the second exterior wall; wherein the first exterior wall is further from the axis than the second exterior wall is from the axis when the collapsible bottle is in the initial configuration; and wherein the first exterior wall moves towards the axis as the collapsible bottle deforms from the initial configuration towards the collapsed configuration; wherein the first exterior wall and the second exterior wall are each intersected by a first plane that contains the axis; wherein the collapsible bottle has a fourth exterior wall and a fifth exterior wall that are each intersected by a second plane that contains the axis, the second plane being perpendicular to the first plane; wherein the collapsible bottle has a sixth exterior wall that is intersected by the axis; and characterized in that the fourth exterior wall, the fifth exterior wall, and the sixth exterior wall have a reinforcement structure that resists deformation of the fourth exterior wall, the fifth exterior wall, and the sixth exterior wall as the collapsible bottle deforms from the initial configuration towards the collapsed configuration.