Abstract: A support device for a cap is formed as a block of compressible, resilient material shaped generally to conform to the inside of a cap and sized somewhat larger than a cap to be supported. The support device is compressed, inserted into a cap, and released to secure the device within the cap. The cap supporting device can be used to support a cap for retail or collection display as well as for transportation or in other instances when the cap is to be protected. Since the cap supporting device of the present application can also be used to support a cap during washing and/or drying of a cap, ventilation holes can be formed partially or entirely through the device. The cap supporting device can be formed as a solid block of material or can be formed as a shell or hollow generally hemispherical block. While the device tends to be self-securing within a cap, it can also be secured within a cap by means of clips which engage a portion of the device and extend over the outside of a cap.