A tattoo is a marking made by inserting indelible ink into the layers of skin to change the pigment for decorative or other reasons. Tattoos on humans are a type of decorative body modification, while tattoos on animals are most commonly used for identification or branding.

Tattooing has been practiced worldwide. The Ainu, the indigenous people of Japan, traditionally wore facial tattoos. Today one can find Berbers of Tamazgha (North Africa), Māori of New Zealand, Arabic people in East-Turkey and Atayal of Taiwan with facial tattoos. Tattooing was widespread among Polynesian peoples and among certain tribal groups in the Taiwan, Philippines, Borneo, Mentawai Islands, Africa, North America, South America, Mesoamerica, Europe, Japan, Cambodia, New Zealand and Micronesia. Despite some taboos surrounding tattooing, the art continues to be popular in many parts of the world.

Body art is art made on, with, or consisting of, the human body. The most common forms of body art are tattoos and body piercings, but other types include scarification, branding, scalpelling, shaping (for example tight-lacing of corsets), full body tattoo and body painting.

More extreme body art can involve things such as mutilation or pushing the body to its physical limits. For example, one of Marina Abramović's works involved dancing until she collapsed from exhaustion, while one of Dennis Oppenheim's better-known works saw him lying in the sunlight with a book on his chest, until his skin, excluding that covered by the book, was badly sunburned. It can even consist of the arrangement and dissection of preserved bodies in an artistic fashion, as in the case of the plastinated bodies used in the travelling Body Worlds exhibit.

Body art is also a sub-category of performance art, in which artists use or abuse their own body to make their particular statements.

In more recent times, body became a subject of much broader discussions and treatments that cannot be reduced to the body art in its common understanding. Important strategies that question the human body are: implants, body in symbiosis with the new technologies, virtual body etc. Scientific research in this area, for example that by Kevin Warwick, can be considered in this artistic vein. A special case of the body art strategies is the absence of body. The most important artists that performed the "absence" of body through their artworks were: Keith Arnatt, Andy Warhol, Anthony Gormley and Davor Džalto.