Hearing loss is a widespread sensory condition with profound consequences that extend well beyond auditory function. Across the lifespan, it has been increasingly linked to adverse cognitive, psychological, and psychosocial outcomes. In children, hearing impairment can disrupt emotional development, social integration, and academic achievement, while in adults and older populations, it has been associated with elevated risks of depression, cognitive decline, and dementia. A growing body of research, including systematic reviews and meta-analyses, has begun to clarify these associations, examining how factors such as age of onset, degree of hearing loss, use of assistive technologies, and coexisting medical conditions shape individual outcomes. This chapter presents a synthesis of recent evidence from global and region-specific studies to provide an up-to-date understanding of the cognitive and psychological impacts of hearing loss throughout life. By presenting these results this chapter aims to answer the research question “What is the impact of hearing loss across the lifespan on cognitive, psychological, developmental, and health outcomes?”