This Perspective provides a concise overview of the field of Luminescence Sensing, which enables highly sensitive, selective, and versatile measurements. The emergence of new luminescent nanomaterials and the prospective of deploying new luminescence-based detection schemes for solving real-world problems, e. g., in medical diagnosis, food safety, and environmental sciences, has led to a continuous growth of the field over recent years. The contributions to the Special Collection on Luminescence Sensing – with a focus on the versatility and advantages of lanthanide complexes for advanced biosensing – serve as an excellent foundation to highlight and discuss recent developments and challenges.