The largest organ in the human body is the skin. The skin is considered an organ because it has some very specific functions like maintaining body temperature and protecting the other organs from bacteria that require some specialized tissues.
The skin of an adult has a surface area of over 23 square feet and accounts for 8% to 12% of your body weight, edging out the liver, your body's second-largest organ, which accounts for approximately 2.4% of your body weight.