This chapter examines the age-dependent variations in long COVID fatigue manifestation, prevalence, and management across different life stages. Drawing from multiple studies and clinical observations, it demonstrates how prevalence rates increase with age, ranging from 5% to 7% in pediatric populations to up to 29.2% in hospitalized elderly patients. The text explores unique challenges and considerations for distinct age groups, from developmental concerns in children to career disruption in young adults and complex care needs in the elderly. Particular attention is given to older adults’ increased susceptibility to long COVID fatigue, examining the roles of immunosenescence, neurological changes, and pre-existing comorbidities. The chapter details various management strategies, including both pharmacological and non-pharmacological interventions, while emphasizing the need for age-specific approaches. It concludes by identifying key research priorities to better understand and address the age-related aspects of long COVID fatigue, particularly in vulnerable populations such as the elderly.