The liver. The liver is your largest internal organ. About the size of a football, it's located mainly in the upper right portion of your abdomen, beneath the diaphragm and above your stomach, but a small portion extends into the upper left quadrant.he liver is your largest internal organ. About the size of a football, it's located mainly in the upper right portion of your abdomen, beneath the diaphragm and above your stomach, but a small portion extends into the upper left quadrant.