Activation of G-protein-coupled receptors (GPCRs) triggers a complex cascade of intracellular signalling pathways that collectively generate a wide range of cellular and tissue responses. G-protein-coupled receptors (GPCRs), the largest group of membrane receptors in humans, play a crucial role in controlling various physiological functions. While the early stages of receptor activation are now well characterized, the downstream molecular mechanisms of GPCR signalling remain only partially understood. Decoding these intricate signalling networks is essential for advancing both receptor biology and therapeutic discovery. In this regard, phosphoproteomics has become a key technology for exploring GPCR-mediated signal transduction on a global scale. This chapter outlines the fundamental workflow of phosphoproteomic analysis, examines current challenges, and considers future opportunities for this rapidly evolving field. By showcasing how phosphoproteomics has provided new insights into GPCR signalling pathways, we highlight its potential to unravel complex receptor networks and accelerate the identification of novel therapeutic targets.