The hedgehog signalling network, first recognized for its crucial function in embryonic growth, is now known as a key controller in tumour biology. Disruption of this system has a role in the formation, advancement, and spread of several types of cancer, rendering it a promising target for treatment. This chapter offers an in-depth analysis of the function and therapeutic consequences of the hedgehog signalling system in cancer. The molecular processes of hedgehog signalling are first examined, and then we explore both canonical and non-canonical routes, clarifying their complex regulatory systems and interactions with other signalling systems. Subsequently, several functions of hedgehog signalling in cancer development are examined, emphasizing its contribution to stem cell upkeep, tumour growth, cell division, viability, and spread. Current treatment approaches focusing on the hedgehog system, such as small-molecule antagonists and monoclonal antibodies, are discussed, along with issues involving drug susceptibility and safety. We investigate new treatment methods such as combination therapy and targeting the tumour microenvironment to improve therapy efficacy and overcome challenges. The work discusses the clinical significance and use of research findings, particularly in identifying diagnostic, prognostic, and predictive indicators. It also covers the results of clinical studies utilizing hedgehog antagonists in different forms of cancer. We provide an analysis of forthcoming developments in hedgehog signalling investigation, highlighting possibilities for customized therapy and outlining important discoveries to propel investigation forward. This chapter offers a detailed guide for investigators, physicians, and students seeking to comprehend the complex significance of the hedgehog signalling system in cancer development and its therapeutic applications.