A capacitive touch sensor includes a layer of electro-luminescent (EL) material arranged between a first electrode and a second electrode, A controller includes a capacitance sensing circuit coupled to first and/or second electrode and arranged to measure a capacitive coupling associated with the first and/or second electrode. The controller is further operable to apply an EL drive signal across the first and second electrodes to cause the layer of EL material between the electrodes to illuminate. This provides a simple structure that is sensitive to objects adjacent a sensing region defined by the first and/or second electrodes, and which may also be readily illuminated by applying an EL drive signal across the electrodes.