Aptamers are nucleic acid sequences that can recognize and bind to analytes with high affinity and selectivity. Intriguingly, a number of aptamers undergo a conformational change within the G-quadruplex motif upon ligand binding. This Minireview aims to highlight interesting examples of luminescent G-quadruplex aptamer-based probes that have been developed in recent years. Various mechanisms and sensing modes are described, and the outlook and future directions of this field are also discussed.