Occupational therapy is one of the allied health sciences, along with physical therapy and speech language therapy. These professions are often found in the same area of a hospital or nursing home, and overlap in many areas of treatment. Occupational therapy (OT) uses occupation (meaning the performing of activities with specific goals), to help people prevent, lessen, or overcome physical, neurological and psychosocial disabilities. It focuses on therapy to help people preform the 'occupation' of daily living, referred to in the field as 'activities of daily living' or ADLs.

While a physical therapist (PT) works directly in rehabilitating the muscles that are damaged or not working correctly, an occupational therapist (OT) works on the activities that an individual wishes (or needs) to perform. Even if a person with multiple sclerosis (for example) may not be 'fixable' by a PT, an OT can work with them to find ways for them to do what they need to do, by finding adaptive technology, modifying the task at hand, or by exercising new skills that will allow them to work around their disability.

OTs work on many issues, including feeding (both infant and adult), positioning, adaptive technology, sensory integration, handwriting, and many other skills that often seem somewhat random to the outsider. OT also covers some of the same ground as recreational therapy, in that both help an individual develop interests and skills for leisure and recreational activities.