A domestic worker or domestic servant is a person who works within the scope of a residence. The term "domestic service" applies to the equivalent occupational category. In traditional English contexts, such a person was said to be "in service". Domestic workers perform a variety of household services for an individual, from providing cleaning and household maintenance, or cooking, laundry and ironing, or care for children and elderly dependents, and other household errands.

Some domestic workers live within their employer's household. In some cases, the contribution and skill of servants whose work encompassed complex management tasks in large households have been highly valued. However, for the most part, domestic work tends to be demanding and is commonly considered to be undervalued, despite often being necessary. Although legislation protecting domestic workers is in place in many countries, it is often not extensively enforced. In many jurisdictions, domestic work is poorly regulated and domestic workers are subject to serious abuses, including slavery.

Servant is an older English word for "domestic worker", though not all servants worked inside the home. Domestic service, or the employment of people for wages in their employer's residence, was sometimes simply called "service" and has often been part of a hierarchical system. In Britain a highly developed system of domestic service peaked towards the close of the Victorian era, perhaps reaching its most complicated and rigidly structured state during the Edwardian period (a period known in the United States as the Gilded Age and in France as the Belle Époque), which reflected the limited social mobility before World War I.