There isn't a single "most important" organ because different organs have different essential functions.Brain – Controls everything in your body, including thoughts, movements, and vital functions like breathing.Heart – Pumps blood carrying oxygen and nutrients to the body.Lungs – Provide oxygen and remove carbon dioxide.Liver – Filters toxins, processes nutrients, and aids digestion.Kidneys – Remove waste and maintain fluid balance.Without any of these, survival would be impossible. However, the brain and heart are often considered the most critical for life.