Copper (Cu) is an essential micronutrient involved in many enzymatic processes that require redox-chemistry. The redox-activity of copper is potentially harmful. Therefore, intracellular copper concentration is kept at a relatively low range, and moderate increases can cause cytotoxicity and even lead to cell death; thus, the uptake, distribution, and elimination of copper are tightly regulated. Copper is acquired from the diet by intestinal absorption and is subsequently distributed throughout the body. About 0.6–1.6 mg of dietary copper is absorbed from the gut per day, with about 50% of dietary copper absorbed. Copper acts as a catalytic cofactor in a wide range of biological processes; mitochondrial respiration, antioxidant defense, bio-compound synthesis, neurotransmitter synthesis, and iron metabolism. In this chapter, we will highlight its metabolism and transport via ATP7A and ATP7B: copper transporters that play a vital role in copper homeostasis and the normal functioning. We will also highlight copper’s functions, what happens with a deficiency and an excess of copper, and we will also discuss genetic disorders of copper such as Wilson’s disease and Menke’s disease.