Protozoa are microscopic, unicellular organisms that can cause a range of diseases in humans and animals. Protozoa-induced diseases affects millions of people worldwide, and their impact on health and society cannot be overstated. This article explores the world of protozoa-induced diseases in detail, examining the different types of protozoa, associated diseases, transmission routes, life cycle, symptoms, causes, and treatments; and discussing the implications for public health and global health.