An adjustable children's booster seat comprising: a child support configured for supporting a child; a frame comprising a base configured for resting on a seating surface of a chair, and wherein the frame is configured for suspending the child support above the seating surface, and the frame further comprises one or more vertically adjustable arms and wherein one or more lateral sides of the child support are rotatably connected to the one or more vertically adjustable arms such that the child support can rotate about a substantially horizontal axis of rotation; at least one tilt control device configured to be actuated by a user between a secured configuration and an adjustable configuration, wherein the tilt control device permits the child support to be rotated about the horizontal axis of rotation when in the adjustable configuration and prevents the child support from being rotated about the horizontal axis of rotation when in the secured configuration; and one or more height control devices configured to be actuated by a user between a secured configuration and an adjustable configuration, wherein the one or more height control devices permit the vertically adjustable arms to be moved upwardly and downwardly with respect to the frame when in the adjustable configuration and prevent the vertically adjustable arms from moving downwardly with respect to the frame when in the secured configuration. a child support configured for supporting a child; a frame comprising a base configured for resting on a seating surface of a chair, and wherein the frame is configured for suspending the child support above the seating surface, and the frame further comprises one or more vertically adjustable arms and wherein one or more lateral sides of the child support are rotatably connected to the one or more vertically adjustable arms such that the child support can rotate about a substantially horizontal axis of rotation; a base configured for resting on a seating surface of a chair, and wherein the frame is configured for suspending the child support above the seating surface, and the frame further comprises one or more vertically adjustable arms and wherein one or more lateral sides of the child support are rotatably connected to the one or more vertically adjustable arms such that the child support can rotate about a substantially horizontal axis of rotation; at least one tilt control device configured to be actuated by a user between a secured configuration and an adjustable configuration, wherein the tilt control device permits the child support to be rotated about the horizontal axis of rotation when in the adjustable configuration and prevents the child support from being rotated about the horizontal axis of rotation when in the secured configuration; and one or more height control devices configured to be actuated by a user between a secured configuration and an adjustable configuration, wherein the one or more height control devices permit the vertically adjustable arms to be moved upwardly and downwardly with respect to the frame when in the adjustable configuration and prevent the vertically adjustable arms from moving downwardly with respect to the frame when in the secured configuration.