Animal mummification was common in ancient Egypt. Animals were an important part of Egyptian culture, not only in their role as food and pets, but also for religious reasons. Many different types of animals were mummified, typically for four main purposes: to allow people's beloved pets to go on to the afterlife, to provide food in the afterlife, to act as offerings to a particular god, and because some were seen as physical manifestations of specific deities that the Egyptians worshipped. Bastet, the cat goddess, is an example of one such deity. In 1888, an Egyptian farmer digging in the sand near Istabl Antar discovered a mass grave of felines, ancient cats that were mummified and buried in pits at great numbers.

Besides Egypt, pre-Columbian bird mummies have been found in the Atacama Desert of Chile, including some next to the oasis town of Pica. These mummies were part of unknown rituals and a long-range trade from the humid tropics across the Altiplano and the Andes to reach Atacama Desert in modern Chile. If bird distribution was as in present, the closest place to Pica from where all bird species could have been captured is Beni Department in northern Bolivia. The mummified birds found in Atacama Desert had their organs removed as well as their tail feathers. Some bird mummies were found wrapped in textiles.

In Europe a 15th-century mummified cat (named Polleke), was discovered inside the walls of a church in the Netherlands. The cat is believed to have been deliberately sealed into the church's structure as a foundation sacrifice; a ritual believed to protect buildings from evil spirits.

Throughout the history of Ancient Egypt, animals were highly respected. According to Egyptologist Herman te Velde, in few other cultures have animals been as influential in so many aspects of life, nor has any culture depicted animals so often in their artwork or writing. It is estimated that one in every four or five Egyptian hieroglyphs relates to animals. Egyptians believed that animals were crucial to both physical and spiritual survival—vital to physical survival because they were a major source of food and to spiritual survival based on how well a person treated animals during their life on earth. Some animals were considered to be literal incarnations of the deities; therefore, it is understandable why Egyptians would have wanted to hold such animals in the highest regard, giving them a proper burial through mummification. In order to determine a person's admittance or denial to the afterlife, the deities would ask a series of judgment questions. One of these crucial questions would be whether they had mistreated any animals during their life on earth. Because of this religious belief, the killing of an animal was considered a serious crime punishable by death. Diodorus Siculus, a Greek historian from the first century BCE, witnessed the lynching of a Roman who had accidentally killed a cat during a visit to Egypt. Understandably, this punishment frightened many Egyptians to the point that if one would happen upon a dead animal, they would flee from it as to avoid the accusation of being its killer.

Long before animal mummies were used as religious offerings, animals in Egypt were occasionally mummified for a more personal reason—as beloved pets that were to keep the deceased company in the afterlife. The most common Egyptian pets included cats, dogs, mongooses, monkeys, gazelles, and birds. Many Egyptians loved their pets, and the customary process of mourning the loss of a loved pet included crying and shaving one's eyebrows. Ancient Egyptian pets were given names just like they are today, a fact evidenced by more than seventy names deciphered in inscriptions identifying pet dog mummies. Pets were often depicted on the tombs of Egyptians, indicating their masters’ affection toward the animals. Egyptians believed that mummification was imperative in order to gain admittance to the afterlife, and therefore the belief was that the mummification of these pets would ensure the animals’ immortality.

Specific archaeological findings have confirmed that pets were mummified. The most famous example of this is the Theban priestess Maatkare Mutemhat’s African green monkey (Chlorocebus aethiops). When her tomb was discovered, there was a small, mummified bundle present at her feet, which was initially believed to be her child. This puzzled archaeologists because Maatkare Mutemhat was a High Priestess who had taken a serious vow of celibacy. If this had been her child, it would have meant that she had, at some point, broken the oath she had taken as High Priestess, raising a slew of other questions regarding her life. Finally, in 1968, an X-ray of the small mummy revealed it to be an adult African green monkey (Chlorocebus aethiops), not a child. Similarly, Maatkare's half-sister, Esemkhet, was discovered buried with a mummified pet—she had a mummified gazelle in her tomb.

Prince Thutmose of the Eighteenth Dynasty was also buried with a beloved animal—his pet cat was mummified and placed in a stone coffin in his tomb. Another Egyptian, named Hapymen, had his pet dog mummified, wrapped in cloth, and placed at the side of his coffin. At the tomb KV50 in the Valley of the Kings, a mummified dog and baboon were discovered buried together, although the owner is unknown.

Egyptians believed that the afterlife would be a continuation of this one, allowing for the transportation of items from this life to the next. In order to bring food to the afterlife, Egyptians would surround human mummies by what are known as victual mummies, made of edible animals. These animals were prepared by dehydrating the meat and wrapping it in linen bandages, which indicated that the animals were food, not pets. The victual animals were not mummified to the same meticulous extent that a pet or human would be, but they were nonetheless carefully preserved using natron and other special salts. This food was included in tombs in order to sustain the deceased person's soul, called the ka, during the journey to the next world. A variety of food has been found in many tombs, mostly breads, meats, and fowl. King Tutankhamun's tomb held several coffin-shaped wooden boxes containing victual mummies, in his case duck and other types of meats.