This chapter examines the definition and types of epistemological fallacies. Epistemological fallacies, such as pseudoscience, conspiracy theories, and paranormal beliefs, lead individuals to hold unscientific ideas. Pseudoscience refers to claims that have a scientific appearance but cannot be verified and lack scientific methods. Conspiracy theories are characterized by a tendency to attribute significant causes to big events and interpret lack of evidence as “evidence that deepens the conspiracy.” Paranormal beliefs are linked to emotional needs and lead individuals to develop supernatural explanations when they feel a lack of control in the face of uncertainty. These epistemological errors become more common when individuals have poor critical thinking skills. The chapter discusses the individual and societal effects of such false beliefs and suggests ways to combat these errors through education and science literacy.