A household deity is a deity or spirit that protects the home, looking after the entire household or certain key members. It has been a common belief in paganism as well as in folklore across many parts of the world.

Household deities fit into two types; firstly, a specific deity – typically a goddess – often referred to as a hearth goddess or domestic goddess who is associated with the home and hearth, such as the ancient Greek Hestia.

The second type of household deity is not one singular deity but a type or species of animistic, which usually has lesser powers than major deities. This type was common in the religions of antiquity, such as the lares of ancient Roman religion, the gashin of Korean shamanism, and cofgodas of Anglo-Saxon paganism. These survived Christianisation as fairy-like creatures existing in folklore, such as the Anglo-Scottish brownie and Slavic domovoy.

Household deities were usually worshipped not in temples but in the home, where they would be represented by small idols (such as the teraphim of the Bible, often translated as "household gods" in Genesis 31:19 for example), amulets, paintings, or reliefs. They could also be found on domestic objects, such as cosmetic articles in the case of Tawaret. The more prosperous houses might have a small shrine to the household god(s); the lararium served this purpose in the case of the Romans. The gods would be treated as members of the family and invited to join in meals or be given offerings of food and drink.

In ancient and modern religions, a god would preside over the home.

Certain species, or types, of household deities existed. An example of this was the Roman Lares.

Many European cultures retained house spirits into the modern period. Some examples of these include:

Although the cosmic status of household deities was not as lofty as that of the Twelve Olympians or the Aesir, they were also jealous of their dignity and also had to be appeased with shrines and offerings, however humble. Because of their immediacy, they had arguably more influence on the day-to-day affairs of men than the remote gods did. Vestiges of their worship persisted long after Christianity and other major religions extirpated nearly every trace of the major pagan pantheons. Elements of the practice can be seen even today, with Christian accretions, where statues to various saints (such as St. Francis) protect gardens and grottos. Even the gargoyles found on older churches could be viewed as guardians partitioning a sacred space.