This course is an introduction to implementation science with an emphasis on its application in global health. Implementation science is the scientific study of methods to promote the systematic update of research findings and other evidence-based practices into routine practice, and hence, to improve the quality and effectiveness of health services. Implementation science requires interdisciplinary efforts, with an intent to understand what, why and how interventions work in real world settings and to test approaches to improve it. This course aims to provide students an opportunity to understand the core concepts, theories and frameworks of implementation health research in global health setting, and what research methods of implementation science can be applied in tackling key global health challenges in low and middle income countries (LMICs). We will discuss implementation challenges such as ethics, research design, data collection, evaluation, quality improvement, policy update and scale-up as a continuum of implementation. Real-life cases in LMICs that applied implementation science will be explored on a variety of topics such as COVID-19, Ebola, tuberculosis, HIV, antimicrobial resistance, diabetes, hypertension, and maternal and child health.