A sanitation worker (or sanitary worker) is a person responsible for cleaning, maintaining, operating, or emptying the equipment or technology at any step of the sanitation chain. This is the definition used in the narrower sense within the WASH sector. More broadly speaking, sanitation workers may also be involved in cleaning streets, parks, public spaces, sewers, stormwater drains, and public toilets. Another definition is: "The moment an individual's waste is outsourced to another, it becomes sanitation work." Some organizations use the term specifically for municipal solid waste collectors, whereas others exclude the workers involved in management of solid waste (rubbish, trash) sector from its definition.

Sanitation workers are essential in maintaining safe sanitation services in homes, schools, hospitals, and other settings and protecting public health but face many health risks in doing so, including from exposure to a wide range of biological and chemical agents. Additionally, they may be at risk of injury from heavy labor, poor and prolonged postures and positions and confined spaces, as well as psychosocial stress. These risks are exacerbated under conditions of poverty, illness, poor nutrition, poor housing, child labor, migration, drug and alcohol abuse, discrimination, social stigma and societal neglect. In many developing countries, sanitation workers are "more vulnerable due to unregulated or unenforced environmental and labor protections, and lack of occupational health and safety".

Sanitation work can be grouped into formal employment and informal employment. Sanitation workers face many challenges. These relate to occupational safety and health (diseases related to contact with the excreta; injuries; the dangers of working in confined spaces, legal and institutional issues, as well as social and financial challenges. One of the main issues is the social stigma attached to sanitation work. Sanitation workers are at an increased risk of becoming ill from waterborne diseases. To reduce this risk and protect against illness, such as diarrhea, safety measures should be put in place for workers and employers.

The working conditions, legal status, social aspects etc. are vastly different for sanitation workers in developing countries versus those in high income countries. Much of the current literature on sanitation workers focuses on the conditions in developing countries.

Those workers who maintain and empty on-site sanitation systems (e.g. pit latrines, septic tanks) contribute to functional fecal sludge management systems. Without sanitation workers, the Sustainable Development Goal 6, Target 6.2 ("safely managed sanitation for all") cannot be achieved. It is important to safeguard the dignity and health of sanitation workers.

A report by World Bank, International Labour Organization, WaterAid and WHO from 2019 defines "sanitation workers" to include toilet cleaners and caretakers in domestic, public, and institutional settings; those who empty pits from pit latrines and vaults of septic tanks and other fecal sludge handlers; those who clean sewers and manholes; and those who work at sewage treatment plants and fecal sludge treatment plants and disposal sites.

Another definition is: "The moment an individual's waste is outsourced to another, it becomes sanitation work."

Since there are various definitions of sanitation, it is not surprising that there are various definitions of "sanitation worker".