In embodiments of on-demand RFID tag activation, an RFID tag is configured so as to enable a person to activate the RFID tag if or when the person wishes. An RFID tag includes an integrated circuit (IC), an antenna coupled to the IC, activation circuitry, and a detachable disable tab. For an example implementation, the RFID tag is in an active state if the IC is capable of responding to an interrogation signal and is in an inactive state if the IC is incapable of responding to an interrogation signal. The activation circuitry is configured to establish the inactive state if the disable tab is attached to the RFID tag or to establish the active state if the disable tab is detached from the RFID tag. The disable tab, if attached to the RFID tag, may impose a short-circuit linkage against the activation circuitry to prevent operation of the tag.