The human organ responsible for producing insulin is the **pancreas**. This glandular organ is located in the abdomen, behind the stomach. Insulin is a crucial hormone that helps regulate blood sugar levels by facilitating the uptake of glucose into cells for energy use or storage. The pancreas contains clusters of cells called islets of Langerhans, which specifically produce insulin and other hormones. Dysfunction of insulin production can lead to diabetes, a condition where blood sugar levels become dangerously high or low, requiring careful management.