This chapter provides an overview of the epidemiology of Type 1 Diabetes (T1D) globally and across different age groups. It highlights the increasing incidence of T1D, which has been reported to rise by 2-5% worldwide, with a prevalence of approximately 1 in 300 by the age of 18 in the US. The chapter discusses various risk factors for T1D, including demographic, geographic, biological, and cultural factors, and emphasizes the importance of genetic and environmental triggers in disease development. It also reviews the clinical course of T1D, treatment options, and the management of complications. Despite significant advancements in clinical care, there is a need for further research to improve care and ultimately find a cure for T1D. Epidemiological studies play a crucial role in investigating the complex causes, clinical care, prevention, and cure of T1D.This chapter provides an overview of the epidemiology of Type 1 Diabetes (T1D) globally and across different age groups. It highlights the increasing incidence of T1D, which has been reported to rise by 2-5% worldwide, with a prevalence of approximately 1 in 300 by the age of 18 in the US. The chapter discusses various risk factors for T1D, including demographic, geographic, biological, and cultural factors, and emphasizes the importance of genetic and environmental triggers in disease development. It also reviews the clinical course of T1D, treatment options, and the management of complications. Despite significant advancements in clinical care, there is a need for further research to improve care and ultimately find a cure for T1D. Epidemiological studies play a crucial role in investigating the complex causes, clinical care, prevention, and cure of T1D.