Potato production faces significant challenges from a wide range of diseases, which have traditionally been managed using synthetic fungicides. However, increasing concerns over environmental impacts, the development of pathogen resistance, and public health risks have led to the exploration of biological control agents (BCAs) as sustainable alternatives. BCAs, which include beneficial bacteria, fungi, viruses, nematodes, and other organisms, offer effective and environmentally friendly solutions by harnessing natural antagonistic relationships and enhancing plant defence mechanisms. Additionally, substances derived from biological materials also fall under this category, broadening the scope of BCAs. This chapter reviews the mechanisms by which BCAs control potato diseases, such as competition, antibiosis, and induced systemic resistance. It further discusses recent advancements and cases of field applications. Biological control is a promising pathway toward more sustainable agricultural practices, meeting the growing demand for eco-friendly farming solutions.