The article reviews the emerging understanding of cilia function in cellular signaling, focusing on three key signaling pathways: ciliary G-protein-coupled receptors (GPCRs), the Hedgehog (Hh) pathway, and polycystin ion channels. Cilia are solitary, immotile sensory organelles present on most cells, playing crucial roles in human health, physiology, and disease. The unique structure and composition of cilia, including their protein, lipid, and second messenger environments, enable them to serve as signaling hubs. The article discusses how defects in these signaling pathways lead to a diverse group of conditions known as "ciliopathies," including metabolic syndromes, birth defects, and polycystic kidney disease. It highlights the importance of ciliary trafficking mechanisms, such as intraflagellar transport (IFT), and the role of specific proteins like TULP3 and the BBSome in regulating signaling. The article also delves into the mechanisms of GPCR signaling, Hh signaling, and polycystin signaling, emphasizing the unique features of each pathway and their implications for cellular function. Finally, it explores the potential for crosstalk between these signaling pathways and suggests future research directions to deepen our understanding of cilia-based signaling.The article reviews the emerging understanding of cilia function in cellular signaling, focusing on three key signaling pathways: ciliary G-protein-coupled receptors (GPCRs), the Hedgehog (Hh) pathway, and polycystin ion channels. Cilia are solitary, immotile sensory organelles present on most cells, playing crucial roles in human health, physiology, and disease. The unique structure and composition of cilia, including their protein, lipid, and second messenger environments, enable them to serve as signaling hubs. The article discusses how defects in these signaling pathways lead to a diverse group of conditions known as "ciliopathies," including metabolic syndromes, birth defects, and polycystic kidney disease. It highlights the importance of ciliary trafficking mechanisms, such as intraflagellar transport (IFT), and the role of specific proteins like TULP3 and the BBSome in regulating signaling. The article also delves into the mechanisms of GPCR signaling, Hh signaling, and polycystin signaling, emphasizing the unique features of each pathway and their implications for cellular function. Finally, it explores the potential for crosstalk between these signaling pathways and suggests future research directions to deepen our understanding of cilia-based signaling.